ed25519-dalek-fiat is used at run time in 122 crates (of which 1 optionally). It is a direct run-time dependency in 5 crates. It's used only as a dev dependency in 9 crates.

Depender (with downloads and own rev deps) ed25519-dalek-fiat version
550 1 recrypt =0.1.0
4 diem-crypto ^0.1.0
1 bytecode-interpreter-crypto ^0.1.0
1 fractal-storage-client ^0.1.0
1 diem-framework-crypto ^0.1.0