Explore, browse, and analyze .NET assemblies.
One of the best tool I have ever used it makes it possible to view the source code of a .NET assembly. Some times better than documentation.

External links

ILSpy Free open source - ILSpy
JetBrains DotPeek Free - JetBrains dotPeek
Telerik JustDecompile Free - Telerik JustDecompile

Red Gates reflector Commercial (but worth paying for - I love the Visual Studio integration and the search capabilities) - Download

Add-Ins

All add-ins
File disassembler - Creates whole projects of an assembly.
Code Metrix - Measure code quality – but most important it adds the "used by" functionality.

Version author:
Mattias Lövström

EPiServer version

All