[twobyfour]

Logo?

Don't know what packages are available to run it on modern OSes, but LogoWriter was a great intro to programming in 3rd grade...

[melle]

Logo - though nice - is too limited for my needs.

If anyone wants to use logo, you can 'import turtle' in Python and start right away ;)

See https://docs.python.org/3.6/library/turtle.html