HOTU has Hell, but I dunno if it's abandonware. It dosen't have a download link, it has a "possible sources" link.
http://www.mobygames.com/game/windows/starsiege
And Starsiege is still for sale.
However Starsiege: Tribes is abandones. Or so says this link. I know he didn't want it, but OTHERS may ^^
http://liberatedgames.com/game.php?game_id=32
If it's not, then someone remove it ^^
Edit: I can't believe I beat Timpsi on those links LOL