The Infrared-HOWTO provides an introduction to Linux and infrared devices and how to use the software provided by the Linux/IrDA project. This package uses IrDA(TM) compliant standards. IrDA(TM) is an industrial standard for infrared wireless communication, and most laptops made after January 1996 are equipped with an IrDA(TM) compliant infrared transceiver. Infrared ports let you communicate with printers, modems, fax machines, LANs, and other laptops or PDAs. Speed ranges from 2400bps to 4Mbps.
The Linux/IrDA stack supports IrLAP, IrLMP, IrIAS, IrIAP, IrLPT, IrCOMM, IrOBEX, and IrLAN. Several of the protocols are implemented as both clients and servers. There is also support for multiple IrLAP connections, via several IrDA(TM) devices at once. The Linux/IrDA project started at the end of 1997 and experienced some major rewrites since then. Please don't expect every feature working straight yet. As far as I know Linux/IrDA is the only open source IrDA implementation available.
Remote Control (RC) via infrared is the aim of the Linux Infrared Remote Control - LIRC project, and also described in this HOWTO.