What began in 1999 as the unofficial 6th game in the Quest for Glory franchise after Vivendi put the series into retirement, had evolved over time into a complete standalone original RPG. If I remember correctly, I think a cease and desist order was issued, but that is just my feeble memory, so don't take it as gospel.
Hero6 was the holy grail to diehard Quest for Glory fans like myself, and the official message was released from DeltaMatrix on the AGS forum as well as on the Hero6 page, that it was officially dead: http://www.bigbluecup.com/yabb/index.php?topic=44704.0
Instead of putting it to rest as some people do, the Hero6 team decided to release the entire source code of all work to the public to do with as they please: Download link : http://s153599580.onlinehome.us/files/Hero6_src_0302.rar
If some industrious team were to pick it up, perhaps it will some day see the light of day, though there is apparently a lot of work to be done with it. As a true fan of the Quest for Glory series, I will be offering a moment of silence for the demise of this most wanted game.