Last updated at 1:54 pm UTC on 17 February 2017
Scratch is an environment built on Squeak in the spirit of Etoys and SqueakLand but geared more towards image and video processing.
Scratch is a project of the Lifelong Kindergarten Group at the MIT Media Lab. Different implementations are available.
NuScratch source on SqueakMap
In 2015 a Scratch version for the Raspberry Pi Raspian OS was released. It is an enhanced version of Squeak version 1.4.
The Raspian September 2015 release contains a new ARM Squeak VM and speed improvements. The BitBlt has been optimized for the ARM architecture.
It uses the Spur VM. It has a GPIO (general purpose input/output) server implemented in Squeak added to drive the GPIO pins.
More about the original project proposal for the period 2003-2007 can be found here.
The versions 1.0 to 1.4 are implemented in Squeak.
A subsequent version then was implemented in Flash, see below 'other versions'.