par-iter is used at run time in 68 crates (of which 8 optionally). It is a direct run-time dependency in 3 crates. It's used at build time in 4 crates (of which 3 optionally, ). It's used only as a dev dependency in 6 crates.

Depender (with downloads and own rev deps) par-iter version
159K 64 swc_ecma_utils ^1.0.2
70K 20 swc_ecma_minifier ^1.0.2
19K 22 swc ^1.0.2