There are a couple I have in mind. Like many techies, I am a huge fan of RSS for content distribution and XMPP for federated communication.
The really niche one I like is S-expressions as a data format and configuration in place of json, yaml, toml, etc.
I am a big fan of Plaintext formats, although I wish markdown had a few more features like tables.
It blows my mind that MPEG 1.0 Layer III is still so dominant.
Count the number of devices in use today that will never support Opus, and it might not blow your mind any longer. Also, AFAIK, the reference implementation still doesn’t implement full functionality on hardware that lacks a floating point unit.
These things take time.
I remember using Xiph’s integer implementation of Ogg Vorbis on my Nokia N-Gage (Symbian S60). I wonder if it’s not a priority for Opus. IIRC, Opus is floats all the way down.
update: it exists.
https://wiki.xiph.org/OpusFAQ#Is_there_a_fixed-point_implementation?