SOSEX is debugger extension for SOS managed code debugger.

SOSEX is another debugger extension targeted at the native debuggers and managed code debugging. It was developed by Steve Johnson and is available as a free download. SOSEX, not surprisingly, stands for SOS Extended. SOSEX adds a set of powerful debugging commands to your arsenal. Examples of such commands include deadlock detection, generational garbage collection commands, and more powerful breakpoint commands.

Downloads:

Source: Introduction to the Debugging Tools