I have been asked this question many times and also found many people have some confusion around different supported version of .NET Framework by IntelliTrace debugging. 
As IntelliTrace is a new feature of Visual Studio 2010 Ultimate edition and VS 2010 came up with .NET 4.0, so many may have got confused that IntelliTrace only supports debugging of .NET 4.0 features. But NO. IntelliTrace is available for .NET Framework 2.0 , 3.0, 3.5 and 4.0. So, if you are creating any application (like Window, Console, ASP.NET) with any framework from Visual studio 2010, you can use IntelliTrace Debugging. Even if you have an earlier application which is based on .NET 3.5 or lesser, and you are running it from VS 2010 Ultimate edition, you can enjoy the IntelliTrace features. For an ASP.NET application based on the targeted Framework version, .iTrace log will be different. Generally for ASP.NET application, IntelliTrace log file name starts with the name of the process which is handling the current request.
Whenever you will debug an ASP.NET application from Visual Studio 2010, if it’s targeting .NET 3.5 or lesser Framework version application log file name will start as “WebDev.WebServer20” and all ASP.NET applications targeting .NET 4.0 will have .iTrace log file name started with “WebDev.WebServer40”. Because all the applications till ASP.NET 3.5 are taken care of by ASP.NET Development Server process WebDev.WebServer20.EXE (Targeted to CLR 2.0 ) and ASP.NET 4.0 application is taken care of by WebDev.WebServer40.Exe (Targeted to CLR 4.0). Similarly, if you are running your application from IIS by opening the application from Visual Studio 2010, your log file name will start with w3wp.exe.
If you open any of the IntelliTrace log files in Visual Studio 2010 as IntelliTrace Summary window, you can see what are the processes being used by your ASP.NET application.
As per the above image, you can see a module list having WebDev.WebServer20.exe, which means, this is an log file that was generated by an ASP.NET 3.5 or lesser version of application.
You can check out my Virtual Tech Days Session PPT on Download PPT – “Debugging Web Application Using IntelliTrace” – Virtual Tech Days – 22nd to 24th November 2010 for more information on IntelliTrace Debugging.
And for multiple versions of ASP.NET Frameworks, read this article:
Thanks
AJ
Filed under:
Debugging,
Visual Studio 2010 
