http://www.citus-cms.org/

https://sourceforge.net/projects/chicomas/

https://www.bloofox.com/

bloofoxCMS is a free open source content management system (CMS). bloofoxCMS is a small and easy to use CMS. It enables you to manage websites and intranet sites in a very simple way. It is slim but also flexible.

http://www.bitweaver.org/wiki/

https://automne-cms.com/

Automne is a true development platform it allows you to build customized applications.

https://www.ariadne-cms.org/

Ariadne is a feature-rich open source CMS with a simple user interface.

http://www.apprain.com/

https://sourceforge.net/projects/adaptcms/

http://freshmeat.sourceforge.net/projects/attension

https://typo3.org/

If you're looking for an open source commercial level CMS you will want to check out Typo3.