On their website, Rockstar has what is titled as "Rockstar Classics," and apparently this is the third volume in the series.
"In 1999, Rockstar Games and Rockstar North (then known as DMA Design) furthered the groundbreaking gameplay concepts established just two years prior in the original Grand Theft Auto - with the release of GTA2. GTA2 expanded on the top-down, open-ended crime world gameplay formula with a host of new features including the advent of multiple rival gangs – seven, to be exact, including the Yakuza, Scientists, Looneys, Rednecks, Zaibatsu, the Russian Mob and Hare Krishnas. Earn your respect with each gang. Reap the benefits with all manner of shady work-for-hire gigs contracted your way. And climb your way to the top of the criminal pile.
Now, longtime Grand Theft Auto fans can revisit this classic entry in the series - and new jacks who missed out on this early franchise title can further discover Grand Theft Auto's roots - absolutely free. GTA2 has been completely optimized for play on modern PCs and is available gratis for all registrants to the Rockstar Games mailing list (rest assured your information will not be shared with any third parties, you will only receive information from Rockstar). Simply fill out the form below and check your email for a direct link to the file (353 MB .zip file, includes install .exe, readme .txt file, and a .pdf of the original PC game manual)."