Two good tools to keep in your toolkit

Most of the time, I get to work in projects already in a Production environment.

Sometimes, the objective of the project is to resolve performance issues or migrated content / functionalities. 

Not often, but it happens, the source code and the SharePoint solutions are not available to you. 

In those hard times, i usually use this two tools:

SharePoint Farm Solution Extractor 

(see it here)

SharePoint Farm Solution Extractor is a great and simple tool that helps you extract the .wsp files in an SharePoint 2007 Farm.

ILSpy

(link here)

A free alternative to the now paid .NET Reflector. It's a very nice .NET assembly browser and decompiler.

If you know any alternatives to this tools or have some tools you use, give me some feedback :)