serde_cow is used at run time in 43 crates (of which 7 optionally). It is a direct run-time dependency in 2 crates. It's used only as a dev dependency in 1 crate.

Depender (with downloads and own rev deps) serde_cow version
154K 109 serenity ^0.1.0
150 1 skua ^0.1.0