Bidirectional compilation - a compiler that can work backwards to enable radical refactoring, possibly into other languages. I'll start with Pascal, because it doesn't really do macros, which break reverse causality. Memex - I want to create a markup language for existing documents that can actually bring an 80 year old idea to life. The main feature is the ability to browse the web and have it all captured and ready for sharing and making copies on demand, something IP lawyers and censors would abhor.
LiveSQL - a database that offers subscriptions to changes, and temporal features. There was an old database back in the MS-DOS days that had the idea of generations of changes to resolve locking and other issues. Maybe that becomes part of this. The main feature is that you could have a query that gives you new versions of the database as others make changes.
Setting up my own electronics repair shop. My friend who I help has been doing this since the 1950s, I need to get my own workbench and things up and running again, it's been decades since I've had my own shop, now that I'm retired, it's time to set it up.
De-hoarding - too much stuff that I won't use, and my child doesn't need to worry about when we're gone. Part of the shop process should be finding someone else to inherit that stuff, and save my kid the grief of finding it a home.
Multidimensional ratings - Imagine a way to rate things on a forum (just to make it easier to start out), but instead of up/down vote, you can make up your own dimensions as well... humour, is_it_political, spam, etc. There are things you really can't talk about because the moderation systems we use globally have to worry about spam of many forms, and nuance gets crushed. I'd like to help address that.
Multidimensional ratings - Imagine a way to rate things on a forum (just to make it easier to start out), but instead of up/down vote, you can make up your own dimensions as well... humour, is_it_political, spam, etc. There are things you really can't talk about because the moderation systems we use globally have to worry about spam of many forms, and nuance gets crushed. I'd like to help address that.