WonderCMS - WonderCMS is the smallest flat file CMS. Completely free, open source, privacy oriented for over 12 years.
Concrete CMS - Concrete CMS is an open source content management system for teams. A website builder with built in tools make editing content easy.
Nibbleblog - Nibbleblog is a powerful engine for creating blogs, all you need is PHP to work.
django CMS - Enterprise Content Management with Django The open-source CMS used by thousands of websites since 2007
WordPress - WordPress is web software you can use to create a beautiful website or blog. We like to say that WordPress is both free and priceless at the same time.
Kirby - Kirby is a website for businesses to use to sort contacts and other information. The site is easy to use and features several details for businesses of all sizes.