I’ve been using lucidchart for making flowcharts and diagrams for years, but I’d like to move to something open-source/self-hosted because A. it’s $100 a year, B. I have no idea how private it actually is, and C. they’ve now messed up my billing and overcharged me twice (had to charge back the first time).

It’d be ideal if I could host it on a server and then use it through a web browser, but even a local app would be fine, as long as it supports windows and linux.