REPLY TO COMMENT


Greg Squire
Well the big three engines have been mentioned

Visionaire
Adventure Game Studio (AGS)
Wintermute

All of those are great engines. Visionaire is probably the best to use for a commercial game as it is now cross platform, well supported and is used by Daedalic Entertainment (a big adveture game studio in Germany). AGS is a good second, the code base is open source and community supported. Also lots of commercial indie games made with it. Wintermute is also good but still Windows only.

The plug-in for Unity called Aventure Creator (mentioned previously - http://www.iceboxstudios.co.uk/adventure-creator) also looks promising. Unity3D is used by tons of developers, is highly supported and cross platform.