I'm en:user:David Gerard. I'm here to help with the documentation, mostly so I can use it myself (a sysadmin frequently tasked with setting up MW) better. If you want to get in touch with me, go to my English Wikipedia home page.
I release all my contributions to this wiki as Public Domain or equivalent.
Doing this for the good of humanity
I'm the volunteer sysadmin at http://rationalwiki.org and there's hardly a day I don't regret taking it on. At least the bit where I write on the wiki is fun. I'm effectively the last maintainer standing of user:Nx's custom RW extension Extension:ImageFilter.
Doing this for a living
I run a pile of intranet MediaWikis at work. Some with custom in-house extensions that the original developer of has long since left. Fun!
For MediaWiki on Ubuntu, I recommend: 1. Install the dependencies. 2. Install from tarball.
Use Leengux, not Solaris. Please. I worry about you.
Expect the Solaris instructions here to improve. I can summarise my work documentation of MW on Solaris as "You really don't want to do this", and suggest you just use a Linux distro with a decent repository instead. Ubuntu or Debian by preference. CentOS 4.5 is surprisingly not-bad if you get a buttload of stuff from CentosPlus. On RHEL5, hit the IUS Community Project.
I expect using http://opencsw.org - a Linux-style dependency-resolving repository for Solaris, particularly Solaris 10 - would make life way easier, if all you have is a hammer. The work wiki is actually running on a Solaris 10 box, though thankfully I didn't do the original installation. I shudder to think what buckets of rubbish the original sysadmin had to install. By hand from sunfreeware.
One thing I'm doing on mediawiki.org is to create redirects and pages that just suggest other pages. This is so that typing a word into the "search" box will give a useful result. Again, my motivations are helpful selfishness, i.e. if it'd be more useful for me it'd be more useful for others. Let me know if I do something that appears unhelpful.