Yes!

PA-RISC Linux is an activevly developed (and working) native port of Linux
to the PA-RISC architecture, which will eventually be merged into the
mainstream kernel tree and into commercial distributions.  HP officially
supports and endorses the project.  Currently, PA-RISC Linux supports
practically any HP workstation, as well as the A180 server.  Support for
Ls and Ns is in the works.  See:

  o <http://parisc-linux.org/>

MkLinux was successfully ported to PA-RISC 1.1.  This project has not been
active since '97:

  o <http://www.openpa.net/other.html#mk>

There is also an HP9000/300 Linux port that has been merged with the
Linux/m68k kernel tree as of about Linux 2.1.119.  The homepage for this
effort is:

  o <http://www.tazenda.demon.co.uk/phil/linux-hp/>

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