Scratch and Squeak!
Today I found a link to Squeak, which is
a modern, open source full-featured implementation of the powerful Smalltalk programming language and environment. Squeak is highly-portable – even its virtual machine is written entirely in Smalltalk making it easy to debug, analyze, and change. Squeak is the vehicle for a wide range of projects from multimedia applications, educational platforms to commercial web application development.
This is being used in (among other places) the laptop being produced for Nicholas Negroponte’s One Laptop Per Child initiative.
I also found Scratch, which is
a new programming language that lets you create your own interactive stories, games, music, and art
Scratch is intended to teach children to program computers, and is therefore set up to provide visual feedback and a whole range of interesting projects. It seems to be based on the idea of getting children to do things to produce effects on the screen, before they realise that what they are doing is programming.