Modula 3 is a missed gem to me. Turbo Pascal was still a thing and C/C++ became popular and it was kind of missed that there was a new language that provided many things that were popular at the time: OOP, or quite new: garbage collection plus lots of free documentation. Computer books were very expensive.

I tried it recently and discovered that it also came with a multi-platform (Windows/Unix) GUI/Graphics library called Trestle.

https://modula3.github.io/cm3/src_reports/src-069.pdf

This GUI library from the beginning of the 90th still works :-D