Tax software. It's the only reason I keep a windows VM.

Openly available traffic data that follows a reliable standard.

for me the most critical ones are replacements for discord and microsoft teams. for discord the critical piece is the login - people don't want to make accounts on each server, so until we have proper federation with a good user experience people won't actually move off it.

for teams i'm sure theres projects in development, i just don't know them or their status - all i know is that i want a project to combine several specialized FOSS services (jitsi is great, and there's lots of other collaboration tools for email/calendar/chat) into one nice unified frontend that is actually reasonably easy to self-host and maintain.

A high performance RISC-V CPU core.

A printer or printer firmware. There was a discussion about this elsewhere on lemmy, of course this would be difficult and expensive but it would be very cool

Leadership: What is important, what redundant projects should be joined or axed and their developers merged.

I have no clue yet if an open source solution exists, but I'm just getting started volunteering with a local animal rescue, and they definitely need a better solution for records management.

I would really like to see something like Jellyfin/Komga but for sheet music. There’s a software in early development called Sheetable that stores it in PDF format, but I really want to see something that has MusicXML support so that sheets can be played back.

Something similar to splitwise.

Idk if there's a os music sheet software somewhere but if someone know one i am interested

A mesh network internet, it's more of a hardware, security, and adoption problem but at this point there's enough wifi overlap in most residential areas that entire towns could have their own local internet without needing the ISP model at all.