Blogs:
b2  (visit site for full details)
b2evolution  (visit site for full details)
Nucleus  (visit site for full details)
pMachine Free  (visit site for full details)
WordPress  (visit site for full details)

Portals/CMS:
Drupal  (visit site for full details)
Geeklog  (visit site for full details)
PHP-Nuke  (visit site for full details)
phpWebSite  (visit site for full details)
Post-Nuke  (visit site for full details)
Siteframe  (visit site for full details)
Xoops  (visit site for full details)

Customer Support:
Crafty Syntax Live Help  (visit site for full details)
Help Center Live (visit site for full details)
osTicket  (visit site for full details)
PHP Support Tickets  (visit site for full details)
Support Logic Helpdesk  (visit site for full details)
Support Services Manager (visit site for full details)

Discussion Boards:
Invision Board  (visit site for full details)
phpBB2  (visit site for full details)
YaBBSE  (visit site for full details)

E-Commerce:
CubeCart  (visit site for full details)
OS Commerce (visit site for full details)

Image Galleries:
4images Gallery  (visit site for full details)
Gallery  (visit site for full details)

Mailing List:
PHPlist  (visit site for full details)

Project Management:
PHProjekt  (visit site for full details)
dotProject (visit site for full details)

Other Scripts:
Moodle (visit site for full details)
Noah's Classifieds  (visit site for full details)
Open-Realty  (visit site for full details)
phpAdsNew (visit site for full details)
PHPauction  (visit site for full details)
phpFormGenerator (visit site for full details)
phpLinks (visit site for full details)
WebCalendar  (visit site for full details)