After nearly two years of development, OpenOffice can now be successfully compiled for IRIX!
From the official site:
OpenOffice.org now runs on IRIX!
We currently have OpenOffice.org (1.0.1, and OOO_STABLE_1) working on IRIX. The working version has a small hack to get it going, but we are working towards a solution for the problem. Check the build instructions section for how to build it yourself.
OpenOffice.org is both an Open Source product and a project. The product is a multi-platform office productivity suite. It includes the key desktop applications, such as a word processor, spreadsheet, presentation manager, and drawing program, with a user interface and feature set similar to other office suites. Sophisticated and flexible, OpenOffice.org also works transparently with a variety of file formats, including those of Microsoft Office.
Available in 25 languages with more being constantly added by the community. OpenOffice.org runs stably and natively on Solaris, Linux (including PPC Linux), and Windows. Additional ports, such as for FreeBSD, IRIX, and Mac OS X, are in various stages of completion.
Written in C++ and with documented APIs licensed under the LGPL and SISSL Open Source licenses, OpenOffice.org allows any knowledgeable developer to benefit from the source. And, because the file format for OpenOffice.org is XML, interoperability is easy, making future development and adoption more certain.
See the OpenOffice.org IRIX Porting Site for more information. Hopefully a binary package will be available shortly.