Joe Gregorio's writings (archives), projects and status updates.
The plan is to write all applications in Python (except for the web browser), and a "view source" button should show the Python source for the currently running application. In the tradition of Smalltalk (Alan Kay is on the OLPC board, and has endorsed the project's use of Python) the user should be able to edit any part of a "live" aplication and see the effects of the change immediately in the application's behavior.
Oh, yeah, and the OLPC firmware is written in Forth. Forth!