I know there are a number of Spiderweb fans around here, so thought you might be interested to know that
Avadon:The Black Fortress is currently available as part of the latest Humble Bundle. That means it's pay-what-you-want, DRM-free, you get it for PC, Mac, Linux and Android tablet in one fell swoop and some or all of what you pay goes to charity. Also included in the bundle: influential one-button running game
Canabalt, Japanese tying-things-up puzzle game
Zen Bound 2, rather wonderful slider-puzzle-meets-meccano
Cogs (one of my favourite puzzle games) and if you pay over the average (currently $6.34) you get side-on RTS oddity
Swords & Soldiers as well!
Fantastic value, available for the next 12 days or so:
http://www.humblebundle.com/