It currently weighs in at a mighty 1165 lines, 63 of which are pod documentation, 1080 of which are a data structure.
If you've made it so far you'll be burning to discover that the module is Module::CoreList, and that data structure is a not of which modules shipped with each version of perl.
It's useful for migration, honest.
ps. Version 1.4 is the one to go for, 1.3 is amazingly buggy, my thanks to Roland Bauer in spotting this.