This site is driven with PHP 5, using SQLite 3 as backend. Furthermore, it uses the Bootstrap 3 framework for responsive web design. The icons in the menu top bar were taken from Font Awesome.
The map was generated with TileMill and is displayed with Leaflet and MBTiles, using the MBTiles plugin. The historic geographical boundaries were digitized with Quantum GIS by Alexander von Lünen from TimesAtlas Maps 1922 (in possession by AvL) and combined with data (coastlines and unchanged boundaries) from the Digital Charts of the World data set. Moreover, data for the Bulgarian-Romanian border (two provinces changed after WWII) was taken from EuroGeographics.