.NET Reflector® is a proprietary software utility for Microsoft .NET combining class browsing, static analysis and decompilation, originally written by Lutz Roeder. Red Gate acquired it in 2011 and have since added live debugging of assemblies without requiring original source!
.NET Reflector® was the first .NET assembly browser. It can be used to inspect, navigate, search, analyze, and browse the contents of a .NET component such as an assembly and translates the binary information to a human-readable form.
By default Reflector allows decompilation of .NET assemblies into C#, Visual Basic .NET, Common Intermediate Language and F# (alpha version). Reflector also includes a "Call Tree", that can be used to drill down into IL methods to see what other methods they call. It will show the metadata, resources and XML documentation.
.NET Reflector can be used by .NET developers to understand the inner workings of code libraries, to show the differences between two versions of the same assembly, and how the various parts of a .NET application interact with each other. There are a large number of addins for Reflector.
Though a variety of competitors have come along, Reflector took a quantum leap forward by being the first to provide not just examination of assemblies but live debugging of assemblies with a Visual Studio plugin.
