If you’re building Silverlight applications and need to be able to run Silverlight 2 and Silverlight 3 on the same machine (even though Visual Studio 2008 doesn’t support Silverlight multi-targeting) then check out Amy Dullard’s post.  I won’t go through all of the steps since she outlines them nicely, but here’s an overview:

• Download a .bat file that Amy provides
• Download the Silverlight 2 Tools and install
• Download the Silverlight 3 Tools and install
• Run Amy’s Setup_SLTools_Util.bat file which will generated some “version switcher” .bat files (see screenshot)
• Click the appropriate .bat file to switch between Silverlight 2 and Silverlight 3 versions

I tried it out and it worked great on my box for Visual Studio 2008 SP1.  I noticed that Silverlight 3 controls still show up in the Toolbox when in Silverlight 2 mode but that’s not a big deal. Files are also included to work with Web Developer Express although I didn’t try that out.  It took less than a minute to make the switch between versions which I’m happy to deal with since it beats firing up a virtual machine or dual-booting.  Awesome trick, so thank Amy by visiting her blog!

Note: Visual Studio 2010 will have Silverlight multi-targeting like we have now in Visual Studio 2008 for various applications.

For more information about onsite, online and video training, mentoring and consulting solutions for .NET, SharePoint or Silverlight please visit http://www.thewahlingroup.com/.