Free Visual Studio edition for individual developers and companies contributing to open source projects.

The Advanced Precompile Settings dialog box lets you specify how a web application is precompiled or assemblies are merged.

Visual Studio 2012 and Visual Studio Express 2012 for Web offer improved web publish (deployment) features for web projects. The new features are installed by default but are optional and can be disabled during product installation. If you disabled them during product installation but decide you want to enable them, install the Web Publish Update.

windows installer that includes essential git components + visual studio plugin

open source subversion plugin for visual studio

detailed description of COM registration

Of particular note: "Make Multiple Visual Studio .NET Projects Participate in the Same Web Application"