$ sudo apt-get install libevent
libevent-1.4-2            libeventdb2-dbg           libevent-execflow-perl    libevent-loop-ruby1.8     libeventmachine-ruby-doc
libevent-core-1.4-2       libeventdb-dev            libevent-extra-1.4-2      libeventmachine-ruby      libevent-perl
libeventdb2               libevent-dev              libevent-loop-ruby        libeventmachine-ruby1.8   libevent-rpc-perl