> Afaik, torrentzip library are not open source, no ?
> That's what i understood...

torrentzip is opensource, the project is hosted on sourceforge :)

> But what is the interess of using torrenzip rather than winzip ?
> Avoid some sharing errors (that's what i've read somewhere...) ?

Torrentzip creates identical zip files on every system out there, which means if you compress blah.rom on Windows, Linux, Unix, OSX, the created zip will be bit-identical. Other packers might create smaller zip files like the zip-packer of 7zip or kzip, but that was not the goal of torrentzip.

> What is it for ?
> Help emukidding and pokerom collectors downloading more torrent or maintain your
> set torrentzipped to have only few files to download each updates of
> pleasuredome ?

Probably right. As torrentzipped files are always identical, people only need to download what has changed and people with partial sets can join in and don't need to start from 0%. :)

> If i could, i'd even delete fileinfo 'this torrentzip' add to ziparchives !...
> (i asked for this to Roman but he regrettably said NO).

There might be some tool that can strip comments of a zipfile by hand.

> Or explain the interress ?

Making sharing of roms easier. But I see no use for torrentzip in ClrMame. An option to delete comments in zipfiles would be nice, maybe.

Those who need it can run it by hand in my opinion. I prefer smaller packed zip files anyway. :P