Just started this list. I have a huge list on a local file. Might move some of that here.
Private friends-and-family "social network" with quirky but crazy simple interface to not scare off the elders
I’ve got a bunch of ideas that were sparked by forth and this one I’m actually doing: forth-concatenative (it’s called Meow5).
Write a real OS (doesn’t matter which platform - RPi ARM, i386?) that is a computer game. I feel like mystery genre at the CLI…or maybe a small story RPG…or point and click in a "Windows 3.1 from an alternate dimension"? I don’t know. Lots of neat things you could do with this.
A really terrible low-budget point-and-click mystery adventure game that is unplayable as-is (like they were). But the real game is to hack that game to complete the in-game game. (I feel like I’m not the first person to have this idea, but I’m not sure)
Help Me Home - a more complete idea
Spine Sniffer - where you have to sniff all the spines