OnPay - Payroll and HR that make business a breeze
Bludit - Bludit is a web application to build your own website or blog in seconds, it's completely free and open source. Markdown support.
Viventium - Viventium is a cloud-based payroll and human resource software solution designed for small to midsize businesses.
Grav - The modern open source flat-file CMS
PeopleGoal - PeopleGoal is a cloud-based employee performance management solution.
WonderCMS - WonderCMS is the smallest flat file CMS. Completely free, open source, privacy oriented for over 12 years.