LIRC doesn't, as the name would suggest, have anything to do with IRC (though I think I've seen an IRC client with this name, I'm not sure).
LIRC stands for Linux Infrared Remote Control. It's a library that decodes the signals of many computer-pluggable remote controls.
This allows many multimedia applications, like television viewers, DVD players, music players and so on to have support for actual remote controls. Some programs that can utilize LIRC include xawtv, Zapping and XMMS.
Home page: http://www.lirc.org/