zmq2 is used at run time in 25 crates (of which 3 optionally). It is a direct run-time dependency in 6 crates. It's used only as a dev dependency in 4 crates (of which 3 directly).

Depender (with downloads and own rev deps) zmq2 version
6 lnp_rpc ^0.5.0
1 lnp_node ^0.5.0
farcaster_node ^0.5.0
130 26 internet2 optional ^0.5.0
20 microservices optional ^0.5
alfred-core optional ^0.5
24K 11 zeromq dev ^0.5
zeromq-2sat dev ^0.5
zeromq-twosat dev ^0.5