The AMD64 compiler suite is now included in the distribution, but note that AMD64-specific library code and the like are not yet distributed. A minimal AMD64 CPU server kernel exists at the labs.
A CPU server kernel runs on Marvell's Sheevaplug, Guruplug (but not Guruplug Display yet) and Openrd-client, based on the Kirkwood SoC, and another runs on the IGEPv2 and Gumstix Overo, based on the TI OMAP3530 SoC. USB and flash memory don't yet work on the OMAP kernel due to lack of documentation. Plan 9 now also runs on the dual-core Compulab Trimslice.
Richard Miller has ported Plan 9 to the Raspberry Pi. Kernel source code is available in /n/sources/contrib/miller/rpi/sys/src/9/bcm, an SD card image of a stand-alone fossil file system is in /n/sources/contrib/miller/9pi.img.gz, and a kernel image, which can be used to boot a Pi as a terminal in a Plan 9 network, is in /n/sources/contrib/miller/9pi.
PowerPC 405EP, 405GP, 440GX based on Inferno CerfCube 405 port. CPU server runs on Virtex 4 and 5 FPGAs; available upon request.
One of the Blue Gene ports is available.
Alcatel-Lucent use some PowerPC cards internally, the code for these has been left in the distribution to help others doing their own ports. Again, these are now quite old.
Alpha - Plan 9 ran on the DEC Alpha PC164, it is also believed to have run on the LX164 and with some small modifications on the 500au. More recently a port was done to the Dec Personal Workstation, sd550 http://groups.google.com/group/comp.os.plan9/msg/e690ed5040ae91af though with no graphics support. Only network boot is supported. These are old machines and ports.
MIPS - The second edition supported various MIPS-based platforms, including several then-popular SGI machines. SGI has declined to allow the kernel source to be distributed (unlike the 2e Sun sources, which are available). Tim Wiess has discussed doing a modern port.
iPaq (ARM) - A version for some iPaq models is also distributed; see Installation on Ipaq, but iPaqs are now quite old.
BeBox - Dr C H Forsyth did a port of the Second Edition to the BeBox; detailed info and an image of the system can be found in: http://verso.terzarima.net/plan9/soft/bebox.html
PowerPC iMac - Some students at CMU worked on a port to the iMac with Professor David Eckhardt. Work on the port has (more or less) stopped. In its current state, the port uses OpenFirmware-based device drivers; significantly, it lacks one for ethernet. For more information, see http://www.cs.cmu.edu/~412/projects/9mac/ or contact Prof. Eckhardt.
64-bit SPARC - Tim Newsham has ported the both the plan9 compiler and kernel to the sparc64. The code for this port is available in /n/sources/contrib/newsham:
Supported Platforms - Sun Ultra2 Supported Hardware - HME 10/100 ethernet - HME/FAS366 SCSI - no booting from disk yet - no support for sunlabel disk labels - Z8530 uart serial portThe code was last updated in April of 2005; some work is needed to bring it back in sync with the current kernel tree.
32-bit SPARC - Chris Collins was updating the 2nd edition sparc32 port to the 4th edition. These machines are now quite old and the sparc64 port seems a better bet.
Next Cube - The second edition supported 68k-based Nextstations as terminals; this code has not been updated to the 4th edition.
Vax 750 - The earliest file server port. The compiler binary was recently found but the source appears to have been lost in the mists of time.
Hobbit - A CRISP CPU developed by AT&T, see the entry in the Wikipedia
Compilers also existed for several other architectures which are no longer distributed. Some, like those for the Intel i960 and AT&T 3210 CPUs, where only ever used to program peripherals and thus where not extensively tested. Others, like the AMD 29000, were used for other projects, like ports of Inferno. See 8c(1) for the list of currently distributed compilers.