Yes, they may have built with that, but off of it they run:
CMS - Portals
AngelineCMS
CPG-Nuke
Drupal
e107
eNvolution
Exoops
eZ Publish
ezContents
Geeklog
Jetbox One
LDU
Mambo
MD-Pro
myPHPNuke
Ovidentia
PHP-Fusion
PHP-Nuke
phpwcms
phpWebSite
PHPX
Postnuke
Props
Renegade
RUNCMS
TikiWiki
Typo3
Xaraya
XOOPS
YACS!
CMS - Blogs
b2evolution
bBlog
BLOG:CMS
Nucleus CMS
pLog
Serendipity
Textpattern
WordPress
CMS - e-Commerce
MyMarket
osc2nuke
osCommerce
Zen Cart
CMS - Groupware
dotProject
eGroupWare
MoreGroupware
phpCollab
PHProjekt
CMS - Forums
Blackboard
openBB
Phorum
phpBB
PunBB
Simple Machines
W-Agora
XMB
CMS - e-Learning
ATutor
Claroline
Moodle
Segue
Site@School
CMS - Wiki
DokuWiki
ErfurtWiki
MediaWiki
PmWiki
UniWakka
WackoWiki
WikkaWiki
WikkiTikkiTavi
CMS - Lite
CMS Made Simple
CMSimple
Etomite
Limbo
Rodin
zTml
CMS - Miscellaneous
Coppermine
Gallery
Owl
SugarSales
and they have demos of all these installed for you to check out.
There's also a forum where you post what you desire and the community suggests the best solution based on your needs.
http://www.opensourcecms.com/