Migation of a VB6 application to .NET platform is almost like a rewrite, no matter it is VB.NET or C#. Do you think it will require more effort to do it in Java platform, when compared to .NET platform, since it is a rewrite anyway? Please share your thoughts!
No offence, but you are wrong. Porting to .Net is usually far easier than a rewrite.
Here's the official advice from Microsoft UK:
Performing a complete rewrite to .NET is far more costly and difficult to do well [than converting] ... we would only recommend this approach for a small number of situations.
From a blog post by a Microsoft guy who consulted on rewrites:
Many companies I worked with in the early days of .NET looked first at rewriting driven in part by a strong desire to improve the underlying architecture and code structures at the same time as they moved to .NET. Unfortunately many of those projects ran into difficulty and several were never completed. The problem they were trying to solve was too large
I recommend the following two steps in this order.
Write down the reasons for migration or rewriting. What benefits will it bring? The benefits might be just to keep the development team happy - that might even be a good enough reason, I don't know. Make sure you know, and your managers/users agree.
Check out the Microsoft UK advice with a screencast explaining the 5 basic options for .Net migration. Decide which is best. It may be rewriting, but go into it with your eyes open.
In answer to your actual question: would a complete rewrite be easier in .Net or Java? That mainly depends on which one your team knows best. It also depends a little on whether the application interacts with COM, just like SLaks says.
The effort of rewriting a VB6 app is more than just a question of which language you're targetting. VB apps often rely on COM objects and certain VB-specific library methods which may not have equivalents in Java - but may have some portability in .NET.
Unless you are willing to abandon all of the dependences of the project, you may find .NET an easier target to re-write for, especially if you need to preserve some of the behavior of the existing application which derives from libraries or other dependencies.
Another consideration will be which platform your team is most familiar with - if you have a lot of Java expertise but little or no .NET expertise, then perhaps Java is a good choice for you.
There are tools available that will migrate from VB6 to VB .Net, including the one built into Visual Studio. This tool migrates VB6 to C#. Whatever tool you use, you will still need to do a lot of manual work on the code that the tool outputs, however this is likely to be less work than a complete java rewrite.
Depending on your existing application's architecture, and how well the code is structured, you may decide it is better to completely re-design and rewrite it anyway, in which case there may not be much to choose between .Net and java.
It is important to reduce not just the total effort during migration but also the cost of maintenance after migration. Many factors drive TCO, but all things being equal I think the .NET tools, community, framework, and C# language meet or beat Java in terms of developer productivity, operational managability, and performance -- assuming your are targeting windows OS.
I do not think ease of keeping COM should be the deciding factor either. In fact, I think migrating VB6 to .NET but keeping COM when you do not have to defeats a critical purpose of doing a VB6 migration in the first place: to reduce development costs and risks by moving to a well-supported and viable platform. I will tell you why:
Most of the popular COM libraries and
controls that were used with VB6 have
not evolved in many years; many of
the smaller vendors have disappeared
or if they are still supporting their
wares, they now also offer new and
improved .NET versions.
Living with old COM after migration
means living with additional
complexity in terms of debugging,
builds, and deployment. Also beware that COM
components do not really "speak" .NET
(i.e they do not use .NET types and
conventions) so their use with .NET usually
results in added complexity in the
coding and design.
There still are a few
hold-outs and exceptions to this rule
and a .NET replacement is not the
always best choice, but in general,
migration teams will be able to find
at least one .NET replacement option
for almost every COM component they use.
Taking the time to thoughtfully
evaluate, select and upgrade to one
of those options will pay off after
the migration.
You will not want to interop anything
that is VB6 you plan to migrate. Interoping your own code will lead to a longer,
complex transition and typically
requires back-tracking and
reworking/retesting already migrated
codes. Clearly this is not the most
efficient and understandable upgrade
path.
One more point about having to do "a lot of manual work on the output". The Great Migrations product is a new, programmable migration tool. It is designed to help migration teams incrementally improve the quality of generated code and thus reduce the manual work required to complete the migration project. This includes making the translations more correct, dealing with complex multi-VBP migrations, and also automating the restructuring of VB6/COM code to use .NET components. These features are particularly helpful if the VB6 codebase is very large, changing frequently, and being significantly re-engineered and cleaned up during the migration. This is an agile migration methodology we call the tool-assisted rewrite.
Disclaimer: I work for Great Migrations.
If the application uses COM, it will be far easier to rewrite it in .Net than in Java. Otherwise, it will probably be somewhat easier to port to .Net.
For a more specific answer, please provide more details about your application.
You could also use Jabaco it is a Java Bytecode compiler and it has it's own IDE and syntax very similar to VB6 (nearly the same).
You can find more information at:
http://www.jabaco.org/
http://www.jabaco.org/board/
use a migration tool, like ArtInSoft to just migrate it to .NET.
You can migrate the VB 6 application using the in built VS migration to VB.Net. Try to see if that helps you. If you are looking at migrating VB 6 to C# then I would also recommend what ScaleOvenStove user has recommended.
Related
I know there are some nice new features in C# 4.0 but I can't, for the life of me, think of a compelling reason for either upgrading existing projects or for switching to new projects.
I've seen some posts where people have said that if their hosting service didn't provide .Net 4 that they'd find another provider as .Net 4 was pinicle to their direction <?>.
Now my boss is trying to get me to agree to switch all our production environments to C# 4 and to do it now.
So the question is has anyone either began using, or converted a project to, C# 4 for a compelling reason? Was there a feature that you just had to have that would make your life so much easier?
There are some cool new features in C# 4.0:
Dynamic member lookup
Covariant and contravariant generic type parameters
Optional ref Keyword when using COM
Optional parameters and named arguments
Indexed properties
In his release blog post Scott Guthrie goes into detail about the features of .NET 4 in general. Another great resource is a white paper at http://www.asp.net/learn/whitepapers/aspnet4. However, I'd doubt you are going to need one / any of these new features right away. As Scott Hanselman blogged:
there's a lot of stuff that's new and
added in .NET 4, but not in that
"overwhelming-I-need-to-relearn-everything"
way.
Whether or not you should upgrade is therefore dependent on a variety of other factors. Some reasons that spring to mind:
Standardizing your development environment on a single platform VS2010 over VS2008.
Size of the .NET Framework is substantially reduced
Speed improvements if you are a Visual Studio Tools for Office developer
An open dialogue with your manager seems appropriate to understand his reasoning for the upgrade. I'd argue that because it's shiny isn't a compelling reason.
As a reference this dated Stack Overflow question "Why not upgrade to the latest .net framework" provides the inverse to your question.
Quite frankly System.Collections.Concurrent has made developing multi-threaded applications a breeze.
The new and improved System.Linq.Expressions makes writing dynamically compiled code seem like child's play.
The new named parameters feature means I can have big constructors and not get confused as to what each parameter is. Immutable objects are just that much easier.
Surprisingly not mentioned:
PLINQ
Task Parallel Library
Is your question specific to C# 4.0, or .NET 4.0?
In C# 4.0 there are only a couple of really nice new features. Covariance/contravariance is not useful all the time, but when you run into a need for it, it can really save a lot of pain. Optional method parameters can reduce a lot of ugly method overrides, and make certain method calls a lot cleaner. If you're using COM or IronPython or any of a few similar frameworks, the dynamic keyword can also be a real lifesaver.
.NET 4.0 in general has a ton of really interesting features across a variety of frameworks. Foreign Key support in Linq to Entities, for example, is making life a lot easier for us. A lot of people are really excited about POCO support. They also added support for some of the LINQ methods (e.g. Distinct) that were previously missing from the Entity Framework.
So it will really all boil down to which frameworks you're using and how you're using them, and how expensive it will be for you to make the switch.
First, what is compelling to me may mean nothing to you. Having said that, I would upgrade Visual Studio if budget allows. In fact, personally I think there is a huge career risk in staying with a company that doesn't keep your tools up to date. You will fall behind in your knowledge of the field without access to the latest tools.
As for converting all your projects just to convert them it seems like folly to me. Putting aside all the extra work distribution (and upgrading the machines to have .NET 4), you have to consider the chance that you will have something go wrong. (And if you are like me some things must be called from 3rd party programs using .NET 3.5 making them unable to convert.)
My first rule would be that nothing is converted unless you are working on it anyway. But I would seriously look to convert anything that could use improvement from either parallel code, or COM interop.
I do have a compelling project that was converted. I had a long running web method being called. In the version that exists now, I return from the method without knowing the results. Instead I gave the user a way to check later. By moving to a parallel foreach loop this works much better and I can let the user know if there were any errors.
The same project is also being converted to use RIA services which have greatly improved and reducing the amount of my own code.
I upgraded for the same reason everyone else did.
...so I can put it on my resume :)
If you're starting a new project today, it's probably best to start it on 4.0, since down the road you will have to migrate it at some point anyways (assuming it stays around long enough, older versions of .net will simply stop being supported).
C# 4 implies other things.. depending on your project... WCF 4, WPF 4, ASP.NET 4, MVC 2, Entity Framework 2, etc.. So don't just look at C# as the reason to change, you also have to look at the whole stack. If there's still nothing compelling, then staying where you're at is probably a wise choice.
If you're doing WPF / Silverlight, I would definitely recommend upgrading to Visual Studio 2010 (I know, you can write .NET 4.0 code without an IDE, but that's an edge case if ever there were one).
The multi monitor support is nifty but buggy. I spend a lot of time trying to get windows to refresh.
In terms of language, the COM interop (as #Gvs mentioned) is also vastly improved with the dynamic datatype and optional parameters.
UPDATE: Multiple monitor support is pretty rock solid with VS 2010 SP1.
If you can get your boss to pop for the $10,000+ Visual Studio Ultimate Edition, IntelliTrace is a compelling reason to upgrade your environment and justification enough the for investment.
COM integration is much easier with the dynamic datatype, and optional parameters.
For me there are two things:
optional arguments -- because I am sick of polluting classes with X versions of the same method (overloading)
dynamic keyword -- because the expressiveness of generics in C# is a joke, this way I can at least "write what I mean" without hoops, of course with execution speed penalty
The more compact the code (i.e. if you express the idea without addition "oh, how to avoid limitation Y of the language"), the better, because the code is much easier to maintain and it is harder to make a stupid (or worse) mistake.
There are no compelling stability or security reasons to switch. Shouldn't that be your boss's concern?
I am quite aware of both java and C# .Net .when i try to create a new windows application which are the factors that decide which technology should be opted?
I know of one thing ,for great and faster UI development Visual studio helps a lot.
There are several factors I would consider...
What are your programmers used to working with already? What third party libraries are you likely to need, what's available on both platforms?
Does platform independence matter to you?
Would LinQ be advantageous?
If you're starting from scratch, costs for the platforms?
Both platforms have strong communities around them...
Hope this helps...
Dotnet is pretty much native in Windows which obviously makes it more suited to writing Windows programs. Using Java in a Windows-only environment makes it much harder for you since it effectively just adds another unnecessary API layer.
You will soon realise that all integration points between your Java code and Windows are a bit problematic. For instance, creating installation programs, access file system, reading/writing the registry, starting/stopping services, task bar icons, using Windows GUI components (media player, IE...), help file system...
It all boils down to this imo: The Dotnet framework is much richer in terms of functionality than the Java dito, mainly becuase Java is cross-platform and thus needs a "one-size-fit-all" approach to its API. My experience is that you will only get frustrated trying to "emulate" a Windows native program in Java.
Choose the one with which you are most familiar. The two platforms are different enough that skills from one does not transfer easily to the other.
In any case, try making a trivial application in both your scenarios and see how it works for you. The initial impression is important as it is probably indicative of how well the rest of the work will be.
It also depends on what kind of windows application you want to build. If it's just a question of building a simple standalone application then, considering you know both languages equally well, I wouldn't hesitate and would go for a 100% microsoft solution, especially if you have to do specific things like accessing ActiveDirectory, the windows registry, etc.
Not that you can't do it in Java : you can always use AD through LDAP in Java for example, but the APIs are just "a bit" more complicated than the .Net ones (try to decode objectSIDs in Java without a few tricks).
Now if you have to build an enterprise app. I just feel that popular frameworks like Spring and Hibernate are always coming out after their Java counterparts (disclaimer : this is a personal opinion; I didn't do any research on this, thoroughly comparing frameworks in both languages, but that's just the feeling I have). I don't know how good the .Net implementations are though, so I don't have a point of view on that. I just remember writing .Net 2.0 apps and not liking ADO.Net at all.
My view is that the frameworks I like do exist in both languages, but they are first developed for Java, then ported to .Net.
Now I'm not the kind of developer trying to defend his favourite language over the others. If I don't have external constraints to develop, then I choose whatever language gets my app up and running faster and in the most efficient way.
...But with java you will have crossplatform application on scratch.
Also coding UI in java is not difficult - if you read some guides before and use some frameworks as swing application framework or SWT framework.
If its Exclusively for Windows then .Net is best bet.
Yeah for a pure cross platform application Java can't be beat, but if you can manage it Silverlight is a subset of WPF and a pretty compelling cross-platform proposition on its own.
Productivity-wise I think WPF has an edge as it has a nice XAML markup language that can be easily created with the built-in designer in VS.NET or integrates nicely with MS' suite of expression products.
I intend to write a small application to scratch a personal itch and probably make the life of some colleagues easier. Here is what I have:
10+ years of experience in C
Plenty of experience in programming against the Win16/32 API in C from the Win3.1 to 2000 days.
C library written by myself already doing about 75% of what the application shall do.
What the application shall do:
open a binary, feed it into the mentioned library.
take the resulting text output and feed it into a new Excel Workbook.
apply some formating.
integrate nicely with the Windows environment (availability in "Open With...", remember some stuff using the registry etc.)
(maybe later) before giving the CSV data to Excel, parse it by looking up the meaning of some values in an XML file.
Except for the XML parsing part I have done all of that stuff before including COM / Office Automation in C/Win32. There is a lot of boilerplate code involved, but it is doable and the result will be a pretty small application without the need for an installer.
So why even think about C# / .Net?
no experience with parsing XML
the promise of less boilerplate code for the Windows and Excel stuff (yes, I have done C++ with OWL, MFC, ATL etc. but I am not going there anymore - not for free/fun)
Since I have also experience with C++, VB(not .Net) and a little Java / Objective-C I suppose learning C# will all be about the .Net libraries and not actually about the language.
My considerations so far:
Learning .NET might be fun and might result in less code / first steps in a more modern environment.
Sticking with what I know will lead to a predictable outcome in terms of effort and function (except for the optional XML stuff)
VB looked great at the beginning until the projects where about 80% done, then the pain started and the DLL coding in C. I am concerned history could repeat itself if I choose .Net.
My primary objective is the functionality. Effort is a concern. The XML parsing is optional.
Please advice.
Update: one thing I forgot to mention explicitly is that I am also worried about easy deployment of the tool to my co-workers. With Win32 I am pretty sure I can come up with an EXE file < 1Mb that can be easily emailed and does not require installation. With .Net not so much. Can I create the necessary MSI or whatever in Visual Studio Express (free) or do I need 3rd party tools?
as others have your question mostly covered, I'd just like to quickly comment on your considerations:
Learning .NET might be fun and might result in less code / first steps in a more modern environment.
Totally agreed. It is definitely fun and usually it does result in less code. The investment you make now will certainly benefit you in future projects. It is way faster to program in .Net than in C. Not only it is easier, but it is also safer. You are isolated from many programming errors common in C mostly related to memory mismanagement. You also get a very complete managed API to do stuff you would usually need to build your own framework.
Sticking with what I know will lead to a predictable outcome in terms of effort and function (except for the optional XML stuff)
Hence your indecision. :-)
VB looked great at the beginning until the projects where about 80% done, then the pain started and the DLL coding in C. I am concerned history could repeat itself if I choose .Net. My primary objective is the functionality. Effort is a concern. The XML parsing is optional.
.Net is an entirely different beast from VB. Most of the things you wouldn't be able to do in VB, or at least do them easily, are supported by .Net. For instance, Windows Services are a snap to build in .Net. Socket programming is also supported, but there are very few reasons to do it yourself, as you've got loads of communication APIs with .Net. You've got web-services, .Net Remoting, MSMQ management, and more recently WCF. Proper multithreading is supported by .Net, unlike the idiotic apartment model in VB. In case you really need to go low level, you can also actually use pointers in C#, inside of unsafe code blocks, even though I would never advise to do so.
If you really need to do things in C, then integrating is also relatively easy. You can create COM objects and use interop to work with them from .Net. You can also interact directly with plain ol' dlls using DllImport. Using www.pinvoke.net makes it easier.
When I developed in VB, sometimes I also had to go back to C++ to do stuff that I wasn't able of doing in VB. Since I began programming in .Net, the only extremely rare scenarios I would need to go back to C++ were when I needed to use legacy COM components that used types I was having a hard time to marshal via interop. I wouldn't worry about history repeating itself.
If you're using COM, you may be interested in using C# 4.0 instead of earlier versions - the downside being that it's only in beta. But basically it makes COM stuff somewhat less ugly for various reasons.
I'd expect there to be plenty of good C libraries for XML parsing by now. I would expect the main benefit to actually be the knowledge gained. I doubt that you'll actually produce the code faster for this project, but the next one may well be a lot quicker.
How much do you care about learning new stuff?
It sounds like an ideal project for learning C# & .NET.
You know most of what you need to do so you can use that to gain a base level of understanding of C# & .NET which you can then apply to the stuff you need to learn.
As Rune says though, a key driver could be the timescales. If this is something you need in a hurry then coding it in C & using win32 directly might be the answer.
Sorry I couldn't be more definite.
I think you should use C#. With your experience the learning curve won't be too steep. The code will ultimately be cleaner (and less of it) than you probably could with C/Win32.
There is probably going to be no problem using your existing C-library with the [DllImport] attribute.
It depends. :-) It depends on whether you want to do this quickly or if you want to learn something new. It depends on whether you will be the only maintainer of the code or if others will maintain it in the future. It depends on how complex your xml handling will be and on how complex the COM automation is.
You will probably get a working application quicker if you do it in C than in C#. Both since you have much of the stuff needed already in place and since you know C well.
But this project sounds like a good match for C# and .Net. .Net has great support for XML and COM interop is easy but clumsy in C# (much better in the next version!). So if you are interested in learning C# and .Net this would be a good project to do so.
I would definitely do this in .Net and probably C# (but I am biased). Using .Net would probably result in code that is easier to read and maintain and most probably easier to write. So if you are interested in learning C# I would suggest you go for it!
Edit:
You worry about the size of the executable if you write it in .Net. I doubt that will be a problem, for most if not all of the libraries you will use for a project like this will already be installed on your computer. 1 Mb is rather large for a .Net executable, event for a big project.
a short notice on the installation. .NET is as default xcopy-able so you wouldn't need an installer for the exe to be usable. Mail it around (or with the next release of the .NET framework optionaly leave it on a network share)
You could look at building a hybrid system that uses C++/CLI and C#. C++/CLI provides a nice bridge between the two and lets you easily split different parts of the system between the managed and unmanaged worlds.
Not sure if the setup projects are included in the free versions of visual studio. But you could use clickonce (included with the framework) or WIX (open source XML based msi creation tool).
learning C# will all be about the .Net libraries and not actually about the language
No there are many things you need to learn about the language (delegates , events , generics ...) and also it is object oriented and it manages the memory by itself and yes no pointers :)
anyway C# and .NET are great all you need is some effort to get up to speed
Here's the deal: I'm in the process of planning a mid-sized business application that absolutely must support Win2k. AFAIK, official .NET support for Win2k was scrapped a while ago (IIRC, it stopped at version 2.0).
Now, I already wrote (ages ago) libraries in C++ that allow me to accomplish the end result (i.e., finish this project) just as quickly as if I was writing this application with the help of the .NET Framework -- so .NET's RAD "advantage" is almost negated.
I'm sure a lot of people here deal with business applications that need to support old OS's. So, given my library situation, what advantage(s) are there for me in using .NET over native C++ and vice versa? I'm just not sure which of the two is right for the job -- because it seems that I could use either. Then again, there's that framework support issue to deal with...
I will gladly add more information, if required.
The last .NET version that runs under Windows 2000 is .NET 2.0 SP2. It does include the features required by System.Core.dll (that is part of .NET 3.5).
The answer is YES, you can use .NET 3.5 SP1 under Windows 2000 if you're not going to use .NET 3.0 libraries (WCF, WF, WPF, CardSpace). But you have LINQ, LINQ to XML, LINQ to SQL.
The only thing you need to do is to deploy three core .NET 3.5 SP1 files:
System.Core.dll
System.Xml.Linq.dll (LINQ to XML)
System.Data.Linq.dll (LINQ to SQL)
Disadvantages of this method (read carefully):
Not sure whether it's permitted or forbidden by the EULA (end-user license agreement)
This scenario is not supported by Microsoft.
I'd look to see if Mono (mono-project) works for you. i.e. runs on win2k - if it does it would allow you to port your app to MS .NET and later OS versions should the need arise later in the project. Any .NET is going to be easier than C++ IMHO :)
The biggest difference is that you are (or your boss is) more likely to find developers to maintain your .NET code after you move on to other things.
C++ has the advantage of giving you job stability - although that might not be what you want. :)
I think, given your situtation, it boils down to what you feel more comfortable in writing. If C++ is a comfortable language for you, do that. It will help get you into the code and make it easier to finish.
I would also take care to keep the future in mind. If the Win2K requirement drops that might require you to rewrite if you wrote in C++. It might not. Just keep it in mind while you decide how to proceed.
You can develop with .NET but set the compiler options to target the .NET 2.0 framework. If the OS gets upgraded in the near (or far) future, you can upgrade your program to target the 3.5 framework. I would go this route as it allows for easier future maintenance by others.
Have you considered Delphi? You can download Turbo Delphi for free and it you can easily write code targeting Windows 2000. With Delphi, you'll get an excellent RAD (arguably better than anything you'll find in C++...unless you use C++ Builder).
Delphi creates native code, and has no runtime requirements.
Of course, the downside is if that you don't know Delphi (which is Object-Pascal) you have to familiarize yourself with a new language. However, if you know C++, you'll feel at home in Delphi in no time.
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Closed 9 years ago.
Has anyone ever written an application bigger than its .NET luggage?
People used to criticize VB6 for its 2 MB runtime but it rarely dwarfed the app it accompanied.
Today despite having Vista on my machine I had to download 35 MB of the 3.5 framework and reboot to then try out an app half that size.
When you factor in the decreased source code security I wonder why anyone would anyone develop a windows application in .NET rather than in a language that allowed for the building of native executables.
What is superior about .NET that outshadows these drawbacks when it comes to writing applications to run on Windows?
PEOPLE: Please note that this was written in February, 2009, and what is said was appropriate at that time - yelling at me in late 2012 (3+ years later) is meaningless. :-)
Delphi has some considerable advantages for Win32. Not that .NET apps are inherently bad, but try:
running a .NET app (any version) on Win95/ME, where .NET doesn't exist (AFAIK)
distributing any small ( < 1.5 MB) .NET app (yes, floppy drives still exist)
providing any .NET app on a system that has no Internet access (yes, they exist)
distributing your .NET apps in countries without widespread high bandwidth
keep people from seeing your source code without spending a ton of dough (Reflection, anyone?)
Garbage collection in .NET might be really nice, but anyone who knows anything about programming can also handle manual allocation/deallocation of memory easily with Delphi, and GC is available with reference-counted interfaces. Isn't one of the things that brought all of the non-programmers to proliferation the pseudo-GC of VB? IMO, GC is one of the things that makes .NET dangerous, in the same way VB was dangerous - it makes things too easy and allows people who really have no clue what they're doing to write software that ends up making a mess. (And, before I get flamed to death here, it's great for the people who do know what they're doing as well, and so was VB; I'm just not so sure that the advantage to the skilled outweights the hazards to us from the unskilled. )
Delphi Prism (AKA Rem Objects Oxygene, formerly Chrome) provides the GC version of Delphi that those who need it are looking for, along with ASP.NET and WPF/Silverlight/CE, with the readability (and lack of curly braces) of Delphi. For those (like me) for which Unicode support isn't a major factor, Delphi 2007 provides ASP.NET and VCL.NET, as well as native Win32 support. And, at a place like where I work, when workstations are only upgraded (at a minimum) every three years, and where we just got rid of the last Win95 machine because it wasn't a priority to upgrade, the .NET framework is an issue. (Especially with company proxy requirements only allowing Internet access to a handful of people, limiting bandwidth and download capabilities, and proper non-admin accounts with no USB devices allowed, all still running across a Netware network - no such thing as Windows Update, and never a virus so far because nothing gets in.)
I work some in .NET languages (C#, Delphi Prism), but the bread and butter both full-time and on the side, comes from Win32 and Delphi.
Okay, I doubt this will persuade you as you don't want to be persuaded, but here's my view of the advantages of .NET over older technologies. I'm not going to claim that every advantage applies to every language you mentioned in the question, or that .NET is perfect, but:
A managed environment catches common errors earlier and gives new opportunities:
Strong typing avoids treating one type as another improperly
Garbage collection largely removes memory management concerns (not totally, I'll readily admit)
"Segmentation fault" usually translates to "NullReferenceException" - but in a much easier to debug manner!
No chance of buffer overruns (aside from the potential for CLR bugs, of course) - that immediately removes a big security concern
A declarative security model and a well-designed runtime allows code to be run under a variety of trust levels
JITting allows the CLR to take advantage of running on a 64 bit machine with no recompilation necessary (other than for some interop situations)
Future processor developments can also be targeted by the JITter, giving improvements with no work on the part of the developer (including no need to rebuild or distribute multiple versions).
Reflection allows for all kinds of things which are either impossible or hard in unmanaged environments
A modern object-oriented framework:
Generics with execution time knowledge (as opposed to type erasure in Java)
Reasonable threading support, with a new set of primitives (Parallel Extensions) coming in .NET 4.0
Internationalisation and Unicode support from the very start - just one string type to consider, for one thing :)
Windows Presentation Framework provides a modern GUI framework, allowing for declarative design, good layout and animation support etc
Good support for interoperating with native libraries (P/Invoke is so much nicer than JNI, for example)
Exceptions are much more informative (and easier to deal with) than error codes
LINQ (in .NET 3.5) provides a lovely way of working with data in-process, as well giving various options for working with databases, web services, LDAP etc.
Delegates allow a somewhat-functional style of coding from VB and C#; this is better in C# 3.0 and VB9 due to lambda expressions.
LINQ to XML is the nicest XML library I've used
Using Silverlight as an RIA framework allows you to share a lot of code between your lightweight client and other access methods
A mostly-good versioning story, including binding redirection, runtime preference etc
One framework targeted by multiple languages:
Simpler to share components than with (say) COM
Language choice can be driven by task and team experience. This will be particularly significant as of .NET 4.0: where a functional language is more appropriate, use F#; where a dynamic language is more appropriate, use IronRuby or IronPython; interoperate easily between all languages
Frankly, I just think C# is a much cleaner language than VB or C++. (I don't know Delphi and I've heard good things about it though - and hey, you can target .NET with Delphi now anyway.)
The upshot of most of this - and the soundbite, I guess - is that .NET allows faster development of more robust applications.
To address the two specific issues you mentioned in the question:
If your customer is running Vista, they already have .NET 3.0. If they're running XP SP2 or SP3, they probably have at least .NET 2.0. Yes, you have to download a newer version of the framework if you want to use it, but I view that as a pretty small issue. I don't think it makes any sense to compare the size of your application with the size of the framework. Do you compare the size of your application with the size of the operating system, or the size of your IDE?
I don't view decompilation as nearly such a problem as most people. You really need to think about what you're afraid of:
If you're afraid of people copying your actual code, it's usually a lot easier to code from scratch if you're aware of the basic design. Bear in mind that a decompiler won't give local variable names (assuming you don't distribute your PDB) or comments. If your original source code is only as easy to understand as the decompiled version, you have bigger problems than piracy.
If you're afraid of people bypassing your licensing and pirating your code, you should bear in mind how much effort has gone into stopping people from pirating native applications - and how ineffective it's been.
A lot of the use of .NET is on the server or for internal applications - in neither of these cases is decompilation an issue.
I've written more on this topic in this article about decompilation and obfuscation.
To name a few:
Automatic memory management, garbage collection
Type safety
Bounds checking
Access to thousands of classes that you will not have to create
OK first up, No one language/platform is ever going to be universally superior.
Specialization will always provide a better use case in certain areas but general purpose languages will be applicable to more domains.
Multi-paradigm languages will suffer from complex boundary cases between paradigms e.g.
Type inference in any functional language that also allows OOP when presented with sub classes
The grammar of C++ is astonishingly complex, This has a direct effect on the abilities of its tool chain.
The complexities of co/contra variance coupled with generics in c# is very hard to understand.
Older languages will have existing code bases that work, this is both positive (experience, well tested, extensive supporting literature) but also a negative (the resulting inertia against change, multiple different ways to do things leading to confusion for new entrants).
The selection/use of both languages and platforms is, as are most things, a balancing of the pros and cons.
In the following lists Delphi has some of the same pros and cons, but differs on many too.
Potential Negatives of .Net (if they are not an issue to you they aren't negatives)
Yes, you need the runtime deployed (and installed), and it's big.
If you wanted a language with multiple inheritance you're not going to get it
The BCL collections library has some serious flaws
Not widely supported outside the MS universe (mono is great but it lags the official implementation significantly)
Potential patent/copyright encumbrance
Jitted (ignoring ngen) start up time is always going to be slower and more memory will be needed.
There are more but these are the highlights.
Potential Positives (again if they don't matter to you)
A universal GC, no reference counting that prevents certain data structures being usable, I know of no widely used Functional language without GC, I can't think of significant language of the last 10 years without at least optional GC. If you believe this is not a big deal you would appear to be in a minority.
A large BCL (some parts not so good as others but it's very broad)
Vast numbers of languages (and a surprising number of paradigms) can be used and interact with each other (I use c#, f#, C++/CLI within one wider application using each where it makes most sense but able to easily use aspects of one from another).
Full featured introspection combined with declarative programming support. A wide variety of frameworks become much simpler and easy to use in this manner.
Jitted - alterations in underlying CPU architecture can be largely transparent, sophisticated runtime optimizations not available to pre-compiled languages are possible (java is doing rather better on this currently)
memory access safety
Fusion dll loading and the GAC for system dlls
Likewise specifically for c#
Con:
Syntax based on C underpinnings
(pre 4.0) late binding solely via inheritance
More verbose than some imperative languages
poor handling of complex embedded literals (regexes/xml/multi line strings)
variable capture within closures can be confusing
nested generators are both cumbersome and perform appallingly
Pro:
Syntax based on C underpinnings
Much functional support through lambdas
Expressions allowing compile time validation of non code areas such as Linq to SQL
Strongly typed but with some Type inference to make this easier
if you really need to unsafe is there for you
interaction with existing C++ ABI code via P/Invoke is both simple and clear.
multicast event model built in.
light weight runtime code generation
The C underpinnings really is a pro and con. It is understandable by a vast number of programmers (compared to pascal based style) but has a certain amount of cruft (switch statements being a clear example).
Strong/Weak/Static/Dynamic type systems are a polarising debate but it is certainly not contentious to say that, where the type system is more constraining it should strive to not require excessive verbosity as a result, c# is certainly better than many in that regard.
For many internal Line of Business applications a vast number of the .Net platform Cons are absolutely immaterial (controlled deployment being a common and well solved problem within corporations).
As such using .Net (and this does largely mean c#, sorry VB.Net guys) is a pretty obvious choice for new development within a windows architecture.
The "simplicity" of developing complex(and simple) applications using it. A lot of basic stuff is already coded for you in the framework and you can just use it. And downloading 35mb file today is much easier than 2mb file 8-6 years ago.
There are a lot of reasons. I don't know much about RealBasic, but as far as Delphi goes:
Less widespread than .NET, smaller development community. Many of the Delphi resources on the net are ancient and outdated.
Until Delphi 2009, Delphi didn't have full unicode support.
I don't know about Delphi 2009, but 2007 didn't have very good garbage collection. It had some sort of clunky reference counting that required some intervention on behalf of the developer. .NET has a much more advanced GC that does virtually everything for you.
.NET has a larger standard library and more up-to-date 3rd party libraries.
.NET languages like C# are arguably better, and certainly easier to understand for those new to the language.
There's a lot of supposed advantages cited by .NET developers here that shouldn't be in that comparison, simply because Delphi has them as well:
Type safety
Bounds checking
Access to thousands of classes (components) that you will not have to create
There are however some things in .NET that Delphi doesn't have out-of-the box, and only some of those can be added by libraries and own code. To name a few:
Support for multiple languages working on top of the same runtime - allowing to choose the matching language for the problem (e.g. functional programming using F#)
Dynamic source code generation and compilation - this is something so alien to Delphi programmers that they probably don't even see how it could be useful [1]
Multicast events
Better multi-threading support (for example BackgroundWorker class, asynchronous delegates)
Seamless support for both 32 and 64 bit processes
Weak references
[1] If you don't know but are interested, check out the home page of Marc Clifton, especially the articles about declarative programming.
Edit: I'd like to respond to the comment by Mason Wheeler:
Re dynamic code: I know that there are solutions to have Pascal scripting embedded in the application. There is however a distinct difference between making parts of your internal object hierarchy available to the scripting engine, and having the same compiler that is used for your code available at runtime as well. There are always differences between the Delphi compiler and the compiler of the scripting engine. Anyway, what you get with .NET goes far beyond anything that is available for Delphi. And anyway, it's not the point whether one would be able to code similar infrastructure for Delphi, the point is that with .NET it's already there for you, when you need it.
Re Multicast events: Exactly, there's ways to code it, but it's not part of Delphi / the VCL out-of-the-box. That's what I was saying above.
Re weak references: You are sadly mistaken. Try to use interfaces in a non-trivial way, creating circular references on the way. Then you have to start to use typecasts and wish for weak references.
Well, the .NET Framework is shared for all .NET applications, so you have it only once on your machine and 35MB are nothing today (compare it to the size of your Vista installation). For your second .NET application you don't have to download it again.
For Windows app, .NET (using C# or whatever) gives you more direct access to the latest and greatest Windows features. It's also very well supported by Microsoft, has a huge community and lots of books written about it.
REALbasic (now Xojo) is for cross-platform apps. Using it just on Windows can sometimes be useful, but that would not be its strength (which is that it's amazingly easy to use).
I don't know much about Delphi.
From what I can see RealBASIC doesn't have much (if anything) in the way of Object Relational tools and probably wouldn't be as good a choice for n-tier, database-centric applications.