What "No-Intro" does is fill some .dat files, to be used with ROM-Managers, with information about the known ROMS released. Often there are more versions of the same ROM dump, but most of them are garbage, some examples may include: bad dumps, hacks, fakes, overdumps, underdumps, and so on. "No-Intro" lists only the best available ROM; it must be a full dump with no faults and no changes to the file, basically just the ROMS that are the closest as possible to the original licensed cartridges.
Our goal is entirely different to yours!
When this project was born it's goal was removing the intros that some pirate groups added to the Game Boy Advance ROMS.
This is why it's called "No-Intro".
In later years, we've covered more and more systems: after all the hard work on GBA, GBC, N64, e-Reader and N-Gage, we opened more fronts of preservation.
You won't find ROMS or other piracy material here.
No-Intro builds and maintain DAT files for clrmamepro and RomCenter ROM managers. DAT file for a given system, when run through a supported ROM manager, allows you to audit/check your own ROM collection status (completion, ROM naming). This is performed by hash comparison (CRC-32, MD5, SHA-1) of your ROMs against hashes listed on DAT file.
No-Intro DAT for a given system only list hashes for ROMs which match as close as technically possible the contents from original media used by the system. All hacked/unofficial stuff is sistematically removed/corrected from DAT as soon as detected.
No-Intro DAT also allow you to rename your ROMs by featuring a consistent naming convention. Accurate and consistent ROM naming is second priority in No-Intro DATs (after listing the best ROM dumps). ROM naming is constantly revised.
DAT-o-MATIC (DoM) allow you to download customized DATs for the currently supported systems, and DATs in latest Logiqx's XML format which contain Parent-Clone information for the systems. These Parent-Clone DATs allow you to create a so-called 1G1R (one game, one ROM) collection form your current one. If you prefer USA ROMs, then EUR ones, then JPN, a list containing USA releases, then the EUR without USA releases and finally the JPN ones without USA or EUR releases will be created for you. All regions with releases in a given system are supported (i.e you could prefer Spain > EUR > USA > Italy > Japan...). DoM also offers GoodMerge XMDB files for the supported systems.