Great program for those who are looking to create their own games.
Remember those great text-adventure games (also called interactive fiction) like Zork made by Infocom in the 80's? Well, anyone who's played them has probably wanted to make their own. Of course, it's fairly difficult to learn all you need to in a programming language to make one of any merit. This is what Adrift is for.
Adrift is very intuitive. All you do it click, type, and click. Start out with the basics. Create a room (right click and select "add room." It's that easy), give it's name. Now create a character. Give him some dialogue and a description. Now create a second room. You've got your own adventure game.
In just half an hour, you can have a decent game created. I've tried a couple of these type of programs, but Adrift is by far the easiest. After only having it for a couple of days, I keep finding all the great features. It's even got a battle system so you can create full fleged RPGs (and have multiple-character parties).
Download it at www.adrift.org.uk