Jazz is owned by Epic.
fact: at the OrangeGame (now one of the part that became Guerrilla Games) Jazz was the first game the director of the killzone franchise (Arjan Brusee ) got involved in while Gears designer (Cliffy B) co-designed this game.
it was published by Epic MegaGames

http://www.epicclassics.com/

...but the prices are higher than what you can expect on GOG. And there may be some format issues.

Vorax

That surprises me a bit. Especially considering that iD and 3DRealms have a longstanding relationship and 3DRealms has some of their stuff here. Also considering that the only reason people buy those games on steam is for the data files. The game engines have long since been replicated in opensource leaving the data files the only reason to pay for those games.

EDIT:
But what's their profit margin? A lot of that stuff looks to be vintage for lack of a better word. And storing that stuff costs money. I'd be surprised if on a $25 sale they had any more profit than what could be made on GoG.

That's interesting, as the person here claims that he has an entirely legal and free to distribute copy of OMF. It may be that he's lying, or that the epicclassics site is just cashing in on a free product. Both are pretty low key websites, so either one may have flown under the radar.

Jill of the Jungle? Very fun platform for its days. I've played the first episode on my 286, and now I'm in search for the boxed version of the entire trilogy....

Diversions Entertainment, the developers of OMF (Epic were publishers, not developers), released it for free a few years back. Sadly their website (omf.com) is down, but you can still see info on the freeware release on the wayback machine.

It's unlikely omf.com will resurface, as DE only released three games (OMF, OMF 2097 and OMF Battlegrounds), none of which will run in a modern OS.

Epic Classics has been distributing those games for a very long time, and appears to be doing so legitimately. However, I don't think there's any published information about whether Epic Classics owns the rights to the games, or whether they are just selling leftover boxed copies of the games.

Pre-Unreal Epic games aren't being sold by any digital distributor as far as I know...

Yeah but Epic is selling the Unreal series on GOG too.

It depends which games you're talking about. In cases where Epic was just the distributor, a lot of those games have likely reverted to the developer. Meaning that Epic might not have the right to distribute those games any longer.

Yeah, it's probably because of the publishers for those games that the unreal games are here on gog.