PMON is a freeware ROM-monitor developed for early LSI Logic MIPS R3000 evaluation boards. Since its creation, PMON has become a very common firmware for MIPS evaluation boards and development systems.
For old information on PMON, visit Phil Bunce's (PMON's designer) website at http://www.PhilBunce.com/pmon . The site has not been updated since 2002 and the code is from 1999.
The original PMON code base is rather old now, supports relatively few boards and is not being actively worked on by a single project team. PMON 2000 has become the unofficial successor of PMON. Everything about the PMON 2000 site is shaky at best. An updated version promised in March of 2005 never materialized. The knowledgebase is a joke and the documentation is a mixed bag. The runtime docs are good, but the instructions for configuring and building PMON 2000 aren't. They mention a "pmoncfg" tool but the source code contains no such tool. CVS access is supposed to be available but is not.
PMON comes with excellent runtime documentation in HTML.
Linksys WRT54G and Asus WL-300g, a WiFi 802.11g AccessPoint (both BCM47XX based) use PMON version 5.3.22 as a Linux bootloader. PMON ported to the BCM47XX is available from the GPL'ed sourcecode for these devices.