ILSpy - ICSharpCode. Decompiler. Console..
dotPeek - dotPeek is a free tool based on ReSharper. It can reliably decompile any . NET assembly into C# or IL code. Download dotPeekCommunity. Materials Newsletters, webinars.
dnSpy - .NET assembly editor, decompiler, and debugger
.NET Reflector - .
MonoDevelop - MonoDevelop enables developers to write desktop and web applications on Linux, Windows and Mac OS X.
CFF Explorer Suite - CFF Explorer Suite is a freeware pack of many developing and editing tools like PE editor, process viewer, etc.