At this time, users of -release/-stable flavors of OpenBSD are limited to Firefox 5.0, Firefox 3.6.18, or Firefox 3.5.19.
No -stable Firefox ports have been committed.
You have three choices:
- Wait for 5.1-release, expected on or about 1 May 2012. You will be able to use Firefox 9.0.1 or Firefox 3.6.25 at that time.
- Upgrade to -current, and use Firefox 3.6.28 or Firefox 11.
- Backport Firefox 3.6.28 or Firefox 11 yourself.
Please note that option 3 requires a significant application integration effort; you will not be able to use a -current ports tree with either a -release or a -stable system. Please read FAQ 15.4.1, very carefully.