It's never been a free online release -- this is a pretty common problem with doujin releases in general, as they generally have very limited physical distribution even in Japan and then tend to go poof completely. So it's a classic instance of piracy happening due to distribution issues rather than price. Only recently has there been more a push for digital sales in Japan from places like DLSite (warning: they're not safe for work) and then more recently on Steam internationally.
The original release was a doujinshi release (back when French Bread still made stuff like Queen of Heart, Drill Milky Punch and Ragnarok Battle Offline -- they actually have nearly 20 years of history now) back in 2002. It was not a good fighting game at all, but it was fairly well put together for a doujin release and ended up being absurdly popular (kind of mirroring what happened with the game it was based on, Tsukihime, which was a release by then doujin circle Type-Moon back in 1999). Melty Blood ReACT was an expansion released in 2003 that added some characters and made the combat less ass -- and they had some NRS levels of patching with the doujin releases, releasing about 10 balance patches for each release (it didn't really help the original release, but they at least got most of the infinities out by the end of ReACT.
Ecole (of Death Crimson infamy), for whatever godforsaken reason gets the rights to publish an arcade version of the game, and that ends up being Melty Blood Act Cadenza which comes out in 2005. First version in the arcade and console, with five revisions total, and with a PS2 and PC release as well (PS2 being based on revision A2, PC based on revision B2). The game actually does really damn well in the arcades and manages to sell over 100,000 copies on PS2, although it's still not quite there yet in terms of being a "good" fighting game (although it's still a huge improvement over the doujin releases).
Another revision gets announced and comes out in 2008, Melty Blood Actress Again. This is when they add the multiple variations for each character (they work as a mix of Alpha 3 ISMs and MKX variations, changing system rules AND movesets for each character) and finally get to the point where the game is a legitimately good game. This got a PS2 port in 2009 (Japannnnnnnn) and was the version used at Evolution 2010.
The final current set of releases is Melty Blood: Actress Again: Current Code which came out in 2010 and had a bunch of updates as well (including one that overhauled a ton of system mechanics), and was only ported to PC as a bonus with Carnival Phantasm, which was one of many (many) spin-off series that Type-Moon produced (although technically at this point so is Melty Blood -- they ended up officially absorbing the game's story and characters into canon back with Act Cadenza).
So French Bread busted their ass on this series for a
long time (over a decade!) and turned the game from a zero to one of the best damn 2D fighters made last generation. Too bad none of them have ever come out internationally, and none of them ever will because the Type-Moon tax is now criminally insane. ;_; Rumor is that they have a sequel/remake on deck to go alongside the Tsukihime remake that Type-Moon is making... so expect that in 20XX.
And for most people in this thread, that's probably way more than you ever wanted to know about some random anime fighter.
