Open Firmware Enabled Computers & Systems:
Apple Computers, Inc. has some Open Firmware related documents at their Developer Website for some of their PowerPC Macintoshes
Motorola, Inc. produces a variety of PowerPC-based embedded products for both VME and CompactPCI
Sun Microsystems, Inc. produces Sparc Open Firmware compatible systems
Open Firmware Enabled Operating Systems:
Linux/PPC: Linux for Open Firmware PowerPC machines
NetBSD/macppc: NetBSD for Macintosh PowerPCs with Open Firmware
NetBSD/ofppc: experimental NetBSD for Open Firmware PowerPC machines
OpenBSD/PPC: OpenBSD for Open Firmware PowerPC machines