http://www.acornelectron.co.uk/haven/cats/acornsoft.html
Okay so I didn't actually own everything on that page, but it was that old Acorn Electron that got me started in computers and programming.
I actually stumbled upon it when looking up procedural animation and I remembered there was a program on the Electron that would create "stick" trees; starting with the trunk and then adding a series branches, then twigs etc. before going on to create the next tree eventually creating a forest on the screen. The astounding thing was that the program was just 10 lines of code.