The graphical user interface is called pybliographic. It provides a simple access to the most common features of the underlying engine, pybliographer and lets you search, sort and modify bibliographic entries.
When pybliographic is opened, you can immediately begin to create a new database. The type of this database will be determined when you will save it the first time.
To add a new entry, you can use the Edit->Add... menu, or click with the right button in the list window and select Add...
You will find more information on the main window's usage in Section 1.3.