.NET Reflector combines class browsing, static analysis, and decompilation in one very productive and popular tool.  Redgate offers this tool for free along with a number of other .NET and SQL utilities.  The developers at Redgate took .NET Reflector one step further when they began development on .NET Reflector Pro, which adds more functionality to the Visual Studio add-in.  The tool recently reached beta status and is moving down the home stretch along with version 6 of .NET Reflector.

.NET Reflector was one of the first assembly browsers (possibly the very first) to arrive on the .NET scene.  An assembly is just one of the .NET components that Reflector can inspect, search, navigate, analyze, and browse.  It translates the binary information into readable form to track down performance problems.  Reflector is also a decompiler.  It decompiles .NET assemblies into Visual Basic, .NET, Common Intermediate Language, and C#.  Reflector includes a call tree for drilling down into IL methods and revealing metadata, resources, and XML documentation.  Overall, .NET Reflector helps .NET developers understand the different code libraries and how various parts of a .NET application interact.

Thanks to it's extensible architecture, there are a large number of addins for .NET Reflector, and many of them are open source.  .NET Reflector includes a Visual Studio add-in that will install when you run Reflector.  This add-in lets you jump to Reflector from your coding interface in VS.  The functionality that comes with .NET Reflector Pro is the ability to debug decompiled code using the VS debugger.  Beta testing is free, but the final version will have a cost. 



To open code in Reflector, you simply click and select "Open in .NET Reflector."  The real magic is in the Reflector Pro debugging feature, which can decompile a whole assembly and generate debug symbols.  The decompiled code can then be viewed and debugged with all of the VS features.  This includes setting breakpoints, inspecting variables, and modifying variables.  VS2010's new IntelliTrace function, which moves through the debugging session history, is also usable with the Reflector-decompiled code.  This .NET Reflector Pro feature could end up being a huge time-saver for developers.

Along with the Reflector Pro beta, Redgate is also working on .NET Reflector 6, which will be able to decompile a lot more things.  Version 6 will support the .NET 4 framework and will be able to browse all the assemblies.  However, it isn't able to decompile to C# 4.0 language features yet.  The Open Cache dialog will show all the assemblies in .NET's Global Assembly Cache.  Finally, version 6 will also have graphical and usability improvements.

.NET developers can try the beta for free and provide feedback on the forums.  An FAQ and a demo for .NET Reflector are available.