Starting in 1996, Seznam.cz is nowadays the biggest web portal on Czech internet. The portal was originally search engine (today number2 in the Czech republic with share rate similar to Google), in 1998 the freemail function was added and since 2001, another functions were added, including maps.

Mapy.cz originally used data from Seznam for the Czech republic and from Navteq for the rest of the Europe. Another parts of the world were not rendered on usable zoom level.

As of the end of the year 2014 they switched from Navteq to OSM in the Europe and added zoom level 15 and 16. They earned 1.5milions of POIs (originally 1milion, 2.5 with OSM).

In the Q1 2015 they started to test in beta rendering of the whole world with OSM data and today their product left beta stage and now is available on their homepage.

OSM data are used everywhere except Czech republic and Slovakia (two countries Seznam.cz is focusing mostly - they are collecting data by themselves and have some business plan with them). The only render is the default map, the other ones are available in Czech republic and Slovakia only (with promises of tourist map for favorite tourist destinations). There is also no Panorama (StreetView like) functionfor the rest of the world nor aerial images.

Seznam.cz promises not only taking the OSM data but also actively contribute: if someone mark a mistake on the map (outside Czech republic and Slovakia), they will repair it in OSM. I have no information if the bugreport needs to be done in Czech or other languages are also acceptable.