What is the name of the module that gives a detailed report of modules and themes installed? There is a module that gives a very detailed view of all the modules and themes installed on a site and the core modules as well. I can't remember the name, but I know it exists because I installed it for testing purposes some time ago.

Can anyone remember the name, or tell me about some other modules which do the same thing so I can check if it is the one?
It sounds like you are talking about the Module summary module for D7. The Used modules for D6 is no longer supported.