liblwt-ssl-ocaml 2.4.3-4 (i386 binary) in ubuntu vivid

 Lwt is a library of cooperative threads implemented in monadic style.
 With respect to preemptive threads, cooperative threads are not using
 a scheduler to distribute processor time between threads. Instead of
 this, each thread must tell the others that he wants to let them
 work.
 .
 This package contains runtime libraries for programs using Lwt with
 cooperative OpenSSL.