Links

Lighting

ESTA owns various lighting ressources.
DMX512.com the source for theatre technical information
So you wanted know all about DMX512 and nobody was telling

Other Linux Lighting Software

Q Light Controller lighting software using QT.
Stage Light Basic formerly Stage Light 2. A simple Lighting Editor and Sequencer using the FLTK GUI and DMX4Linux drivers.
ArtNet for Linux software.
dmx4mplayer a package to control mplayer via dmx.
rmx is a ruby software to control DMX lighting equipment.

Hardware

Lighting-Solutions Provides a good parallel port interface and various other DMX tools. They also have free Hardware, so you can build your own interface.
SoundLight manufacturs a variety of ISA cards and parallel port interfaces.
DMX - 512 PRINTERPORT INTERFACE free hardware.
Enttec have a Ethernet DMX Node and a do-it-yourself USB DMX interface.
dmx4all has rs232 and usb interfaces plus various DMX hardware.
Minidmx another Serial2DMX interface bases on the Atmel 90cxxx series.
Artnet to DMX Controller 6 Universes AD-PRO-6 from SIRS-E.

See also the list of DMX Interfaces from the dmx4linux project.