We're searching for a business Intranet product with a few or many of these characteristics

   - common home page
   - departmental sections with password protection for some content
   - allow designated users to edit specific pages
   - wiki type knowledge repository 
   - company phone list
   - document & image management (uploads, some revision management)
   - incident tracking (IT request/service management)
   - ability to develop and customize (php or java would be best)
   - search capabilities
   - open source & non-priority if possible

For the given needs, I suggest you checkout Twiki. Twiki is extremely flexible, simple to install and personalize. Find twiki documentation here: http://twiki.org/cgi-bin/view/TWiki/TWikiDocumentation Also see http://twiki.org/cgi-bin/view/TWiki/ATasteOfTWiki for convenient intro

If you wish to compare other WIKIs available, see: http://en.wikipedia.org/wiki/Comparison_of_wiki_software You may also use http://www.wikimatrix.org/ to determine between several wiki projects.

Best wishes!