Devine had a great talk about the "why" of Uxn at Strange Loop last year:

https://www.youtube.com/watch?v=T3u7bGgVspM

And there was another talk that used it as an example:

https://www.youtube.com/watch?v=umSuLpjFUf8

Both were great. I'm a big fan of 100R's work. Another language of theirs worth checking out is Orca: https://100r.co/site/orca.html