@andrewnez

I was having a really hard time getting this. "Are they making fun of the fact that it contradicts itself in the last sentence?"

Look up the thing. Duck duck go says:

"Vulpine-lz4 is a Rust library for fast LZ4 decompression, themed after Firefox, with a cartoon fox logo. It's a transitive dependency of Cargo, Rust's package manager, but has only 12 stars on GitHub."

I read the readme.md

"Prepend magic bytes (FOX!)"

Not XOF, so they're not using a cypher. Now I get the joke.