libevent-dev 1.1a-2 (amd64 binary) in ubuntu gutsy

 Contains the header files, documentation, examples and static libraries
 for use in developing applications that use the libevent library.
 .
 The libevent library is an asynchronous event notification library
 that provides a mechanish to execute a callback function when a specific
 event occurs on a file descriptor or after a timeout has been reached.
 .
  Homepage: http://www.monkey.org/~provos/libevent/