Has Carbon been used anywhere noticeable? Last time I heard of it was when Google announced it few years ago, haven’t seen anything getting written or ported to it, though I haven’t read much into it so I might have missed many news.
Naviary on youtube has made just that. Their videos are amazing, mostly going over the theory created by having an infinite chessboard (“mate in omega” and it’s sequel are mind boggling), and some are about the technical aspects of implementing infinite chess. Highly recommend watching them.
I read about typst a few weeks ago. I no longer make math- or formatting-heavy documents anymore, but if I had had this while I was in university, I would’ve loved to use it.
LaTeX is nice, but there’s some things that are an absolute pain to get right or make them look like you want to.
Regarding the API, Spotify does allow free access, but some content and features are restricted to the official apps. For example, personalized playlists such as Weekly Discovery, release radar, daily mixes and the like are not available and return an error. Rate limiting is ok for a personal use case with a custom api key, and maybe some small apps can stay under the limit; developer agreement is also quite restrictive, so they have a bunch of reasons to block you.
Source: I’ve used the API before and built a small tool to help me export my top listened songs and some recommendations to a list, nothing heavy but still made sure to read the docs needed just in case. Still managed to hit the rate limit with a few tens of requests in a minute, though the way they do limiting is weird and difficult to account for.