RedHat 7.1 based
A complete distribution based on RedHat's 7.1, ported by H.J. Lu, can be found at ftp://ftp.linux-mips.org/pub/linux/mips/redhat/7.1/.
Maciej W. Rozycki
A little-endian only distribution is maintained by Maciej at ftp://ftp3.ds.pg.gda.pl/people/macro/ or the mirror ftp://ftp.rfc822.org/pub/mirror/ftp3.ds.pg.gda.pl/people/macro/.
Gentoo Linux is a source based distribution which suports many different architectures, including MIPS. Currently two platforms are supported; Silicon Graphics Workstations, and Cobalt servers.
OpenEmbedded is a source based meta distribution similar to Gentoo, but especially targeted for cross-compilation and embedded systems, including MIPS architectures. http://www.openembedded.org
MIPS maintain a version of the above, including complete installable CD-ROM images, at ftp://ftp.mips.com/pub/linux/mips/installation/redhat7.1/.
The following companies provide commercial, supported Linux/MIPS solutions for the embedded market, on a number of different platforms.
MontaVista provides a commercial-grade Linux-based operating system and universal development platform. http://www.mvista.com/
Linux From Scratch
Build your own Linux from the source code for the Cobalt Raq2 / Qube2. Location for LFS-RAQ2 is located at http://documents.jg555.com/lfs-raq2.
DENX Software Engineering provides the ELDK (Embedded Linux Development Kit), a commercial-grade distribution including U-Boot boot loader, Linux kernel tree, cross development tools and an extensive set of native tools. The ELDK which is Free Software is available for PowerPC, ARM, and MIPS processors and can therefore be downloaded for FREE. See http://www.denx.de/wiki/DULG/ELDK
emlix provides a collection of system software for the Au1100 based F+S NetDCU6 boards and the respective BSP (Board Support Package). It is a commercial-grade distribution including U-Boot boot loader, Linux kernel with an extended driver set, cross development tools for Linux/ia32 (including nano-X aka MicroWindows) and a ready-to-run filesystem for the target. Prior targets for emlix were the NetDCU3 and NetDCU5, upcoming targets (fall 2005) will be the NetDCU8 with an ARM cpu.