mmap is used at run time in 19 crates (of which 7 optionally). It is a direct run-time dependency in 9 crates. It's used only as a dev dependency in 4 crates (of which 1 directly).

Depender (with downloads and own rev deps) mmap version
25K 8 perfcnt 0.1.*
1 easy_mmap ^0.1.1
1 cupi *
cylus ^0.1.1
remarkable ^0.1.1
x86test ^0.1.1
coroutine-rs *
wfbuf ^0.1
perf-count 0.1.*
fit_no_io dev ^0.1.0