GCD is used at run time in 281 crates (of which 36 optionally). It is a direct run-time dependency in 25 crates. It's used only as a dev dependency in 41 crates (of which 2 directly).

Depender (with downloads and own rev deps) GCD version
65K 113 fugit >=2.1, <3.0
28K 15 p3-poseidon2 ^2.3.0
7.5K 3 rp235x-hal >=2.1, <3.0
1.4K 1 rustscan ^2.0.1
1.1K 6 ckb-std ^2.3
1.0K 3 relp-num ^2.3.0
750 1 htb ^2.1.0
500 1 klavier-core ^2
480 1 uu_dd ^2.3
350 1 monument ^2.3.0
180 p3-rescue ^2.3.0
150 typus_fugit >=2.1, <3.0
150 prime_bag ^2.3.0
110 hesp-manifest ^2.3
4 const-frac ^2
1 audio-engine ^2
floating_bar ^2.0.1
1 timestamp-stretcher ^2.0.1
quaru ^2.3.0
miratope ^2.0
miter ^2.0.1
qalqulator ^2.1.0
numerous ^2.3.0
repetend_len ^2.3.0
ucsi ^2.3.0
1.5K 2 stable-hash dev ^2.1.0
250 hfs dev ^2.3