AdvanceSCAN

advscan is a command line utility for maintaining a zipped archive of roms and samples for AdvanceMAME, AdvanceMESS and any other MAME derivative emulator.

The goal of advscan is to obtain a complete and perfect roms and samples archive with differential merging.

Differential merging means that any game has its zip archive, which contains all the rom files, which are not already in the parent zip archive (if exists).

advscan has these features:

Directly read, writes zip archives without decompressing and recompressing them for best performance. Add, copy, move and rename files in the zip archives. Any rom that you have is placed automatically in the correct zip. Recognizes the text files added by rom sites and deletes them. Recognizes the text files added by the rom dumpers and keeps or deletes them as your choice. It's safe. In all the zip operations any file removed or overwritten is saved in the rom_unknown' and sample_unknown' directories and keep for future uses. This will prevent any unwanted remove operation.

but also has these misfeatures:

Supports only roms and samples zipped. Supports only roms organized with differential merging. Doesn't support .chd files in subdirectories.