MonoCMS is a website content management system, just like wordpress, the blogger, joomla etc.
The difference between Monnocms and the above is that it belongs to the category of non database databases. Data processing is done with PHP and stored in XML.
So it uses the server's file system to store data, 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 announced by Panayotis (developer of the project), the new 2.6 version was released.
"Ολοκληρώθηκε η μετάβαση στην έκδοση 2.6, με το νέο επεξεργαστή πρόσθετων αντικειμένων, που δίνει στους χρήστες τη δυνατότητα να επεξεργάζονται τμήματα της ιστοσελίδας τους, χωρίς να χρειάζεται να γνωρίζουν code, simply by selecting pre-installed objects (widgets).
With the release of version 2.6, the number of plugins is small, but it is theme time to install more and more interesting ones. The edit page has been completely changed to support the new feature. Theme files remain editable via code."
For more details, see changelog