One of the things that I needed to do in the past was to write a cross-platform project which had to be consumed from Silverlight and an ASP.NET MVC project. At the time, I was kind of lucky because you could reuse a Silverlight assembly in a .NET project provided that you only used some types (Christian Nagel has a nice post about this feature here).
This feature was nice, but it wasn’t perfect. VS 2012 improves it by introducing the new Portable Class Library project. This new project lets you write and build portable assemblies for Windows 7, Windows 8, Silverlight, Windows Phone and the XBox. Sure, there are still several limitations, but now you can reuse your assembly across a wider range of other projects types. Notice, though, that the assemblies produced by this project type can only target .NET 4 or .NET 4.5. If you’re interesting in getting more info about this new project type, then this will help you understand its restrictions.
And that’s it for now. Stay tuned for more.