A chat program I wrote in 2013/14 that ran within ComputerCraft, a mod for Minecraft. It made use of ComputerCraft's virtual monitor and networking.
Disclaimer: being young, I didn't know about code maintainability or refactoring. I wasn't aware of how to call scripts from within other scripts in CCraft, so the program is literally one script. FacSetup is the installer script, which really existed for its own sake.
Servers could save chat sessions (iirc)
As you can see, the virtual screen was very simple, but you could achieve some pretty neat effects