Tinderbox is a build system tool for Mozilla/Firefox at Mozilla. With Tinderbox, you can see the following:
Who has checked out which module Many developers or programmers can be working on a product, both adding enhancements and fixing bugs.
The status of builds for various platforms Not all platforms are built or available at any given time.
Which platforms are currently broken That is, ones that cannot successfully be built.
The state of various component files and who did what to them This allows finding out who broke what.