mrxvt is now available in irixports – https://forums.sgi.sh/index.php?threads/mrxvt-a-tabbed-xterm-available-in-irixports.50/ Read all about installing, customizing and using it on the forum.
The Dillo browser has been ported. Info and binary is availble: https://forums.sgi.sh/index.php?threads/dillo-browser-binary-available.38/ I posted this to Reddit also: https://old.reddit.com/r/retrobattlestations/comments/cd5x78/sgi_irix_gets_a_new_browser_after_14_years_retro/