Here are some I found and used in my own code:
- itertools
- regex
- anyhow and thiserror (error handling)
- indoc (indented/formatted multi line string literals)
- strum (various derive macros for enums)
- petgraph (for working with general graphs)
- winnow is a great (and fast) parser combinator library.
- bpaf, clap and xflags are three different command line argument parser libraries. Which one to use depends on the needs of the project and if you need to match the behaviour of an existing non-rust program (as I needed to in one case)
LGPL specifically does as far as I understand have some issues when used in rust. In particular the border for the copyleft is dynamic linking. That doesn't work well with rust. I would instead consider MPL where the copyleft border is on a source file level.
That said, I'm not a lawyer!