Etoys is a Squeak app for extending Morphic through tile-based scripts. It evolved out of experiments with Scripting with Players -- The "User-Scripting" Style to help young children learn programming by using manipulating large brightly colored tiles instead of composing instructions through keyboard.
Etoys is a powerful learning tool based on Squeak.
The Etoys system is written in Squeak using the 'active objects' system called Morphic.
In a specifically configured image it starts with the EToys GUI.
If you're interested in the Etoys scripting system and its uses in education, you should look at the Squeakland web site. There are tutorials and a number of other resources there for your use.
You should also get the Squeakland release from that site rather than the releases discussed here if you're primarily using the Etoys environment or working with kids.
Currently work is in progress in an intermediary release the Squeak 5.2 image where some functions will be available while a fully functioning result of the merge is planned for a later version.