The EToy system is written in Squeak using an 'active objects' system called Morphic.
There is a DVD that can be seen on-line that looks at the educational role of Squeak http://www.squeakland.org/resources/audioVisual/. (It's called 'Squeakers' but could as well be called 'Etoyers'!)
Developer image (as of July 2009): http://tinlizzie.org/olpc/etoys-dev-4.0.zip
The EToy version of Squeak can be run either within a browser or standalone. The user interface is modified slightly to make it easier for the novice user. For example there are only 2 flaps: Navigator and Supplies; also selecting the desktop does not bring up a World menu - you have to press the escape key for the World menu. Programing is done using scripts which can be called up for any object from the object's Viewer halo. Tiles representing commands are dragged into a script on the desktop. There are a limited number of control structures available.
Tweak is an enhanced version of EToys for the Omnniuser. Visit the Tweak homepage for further info. An alpha version is availble for experimenting now. Version 1.0 of Tweak is due out in the fall of 2005.
See also the published "Powerful Ideas in the Classroom" book mentioned in Squeak books in print.
Stef Ducasse's "Squeak, Learn Programming with Robot" has an excellent 25 page chapter on the basics of using eToys. His book is available at reduced cost from http://www.bookpool.com/
(Please add more details here, I just wanted to get an EToys swiki page going.)
