Wikipedia
GoodTools
Cowering's GoodTools is a suite of 35 ROM auditing applications for Windows that contain a database listing known software for various video game consoles and home computers.
These tools, released as freeware, have established themselves as an important reference for ROM collectors, especially for older systems that don't have similarly authoritative sources and that have a perfect or almost perfect coverage in GoodTools.
The popularity of GoodTools originated the practice of distributing, instead of single or arbitrarily collected ROMs, the so-called "goodsets", packaged archives of every ROM for a particular platform that GoodTools recognizes.