Rio is used at run time in 9 crates (of which 7 optionally). It is a direct run-time dependency in 6 crates. It's used only as a dev dependency in 1 crate.

Depender (with downloads and own rev deps) Rio version
166K 303 sled optional ^0.9.4
haneru ^0.9.4
sludge ^0.9
xxv ^0.9.2
250 pearl optional ^0.9.4
140 1 vsdbsled optional ^0.9.4
1 mfio-rt dev ^0.9