s2n-quic is used at run time in 19 crates (of which 4 optionally). It is a direct run-time dependency in 14 crates. It's used only as a dev dependency in 1 crate.

Depender (with downloads and own rev deps) s2n-quic version
1.2K pankosmia_web ^1.48.0
1.0K jetstream_distributed ^1.52.0
650 sirang ^1.51.0
340 msgtrans ^1
330 2 jetstream_client ^1.54.0
2 abcperf-generic-client ^1.19.0
s2n_quic_mtls ^1.25.0
2 cryprot-net ^1.37.0
streamfly ^1
jetstream_cluster ^1.47.0
s2n-netbench-driver-s2n-quic ^1
320 2 jetstream_server optional ^1.54.0
300 jetstream optional ^1.54.0
mesquitte-core optional ^1
360 6 jetstream_rpc dev ^1.54.0