ScummVM is an 'Virtual Machine' for playing several classic graphical
point-and-click adventure games developed by LucasArts, Revolution 
and Adventure Soft.

See http://www.scummvm.org/compatibility.php for a full list of Games.

The following freewared games are available via ports at the time of writing:

Beneath a Steel Sky:        games/bass
Flight of the Amazon Queen: games/fotaq

WWW: http://scummvm.sourceforge.net/

-Alex Trull (alexander@trull.com)
