MonoCMS is one content management system websites, just like wordpress, blogger, joomla, etc.
The difference between Monocms and the above is that it belongs to the category of non database systems without base data. Data is processed with PHP and stored in XML.
So uses the server's file system for data storage, which makes it extremely simple, small in size, and very fast.
MonoCMS is made by a Greek web developer who lives in Athens (Panagiotis or Pano z), so at the same time with English he acquired his Greek version.
The first syllable of the system name itself derives from the Greek word "only".
Today, as Panagiotis (developer of project) the news was released version 2.7.
The 3.1 support version comes with improvements to the code, and some extra features.
For more details, see changelog