serial-core is used at run time in 122 crates (of which 18 optionally). It is a direct run-time dependency in 13 crates. It's used only as a dev dependency in 62 crates.

Depender (with downloads and own rev deps) serial-core version
69K 62 serial =0.4.0
66K 3 serial-unix ^0.4
41K 1 serial-windows ^0.4
200 2 flipdot-serial ^0.4.0
190 2 flipdot-testing ^0.4.0
150 nano-mesh-linux-examples ^0.4.0
1 platform-serial-linux ^0.4.0
vcontrol ^0.4
evegfx-cli ^0.4.0
slcan ^0.4
stm32-uart-loader ^0.4.0
draw_bridge ^0.4.0
190 1 flipdot dev ^0.4.0