User Interface (1.4) - Scratch Wiki

Scratch 1.0, Scratch Wiki

Scratch 1.4 programming interface.

Scratch 3.0 in Scratch 1.4 Style : r/scratch

Eng:Scratch 2.0 - Test-Scratch-Wiki

Intro to Scratch

Griffpatch, Scratch Wiki

Scratch, Scratch Wiki

Development of Scratch 1.0 - Scratch Wiki

APL (programming language) - Wikipedia

Bitmap Graphics - Scratch Wiki

Scratch - Snap! Wiki

How to Develop Your Own Block for Scratch 3.0

Scratch Versions - Scratch Wiki