I don’t play games at all anymore these days, but I ran across this repository of open source clones of classic PC games.

Some notable ones from the list that we used to play:

• 0 AD — Age of Empires
• C-Evo — Civilization II
• Interstate Outlaws — Interstate ‘76
• Jedi Outcast Linux — Jedi Knight II: Jedi Outcast
• OpenRCT — Rollercoaster Tycoon
• OpenSkyscraper — SimTower

The world of open source software (and GitHub, specifically) really is amazing. Kids out there the age I was when I played these can now go online and look at the source code to see how they’re made.