grmtools
last updated: Oct 20, 2023
https://github.com/softdevteam/grmtools/
Rust grammar tools; allow you to build a parser from a grammar specification. Inclues lrpar, which is a yacc-compatible parser generator for rust.
Found via this article on good errors in LR parsers, which is linked from Laurence Tratt's response to Just Write the Parser
(It's neat that the way they handle errors in that article is to run a graph search on the grammar, looking for the shortest path to a valid string in the language)