Blue marble is essentially an open source Google Earth desktop application. Idk if it's exactly what you want but it's not terrible.

OsmAnd is the same thing for Android and iOS and it's absolutely wonderful.

OsmAnd on Android, which allows you to download Wikipedia entries for the places on the map.

If you are technically inclined, there's QGIS. It's a steep learning curve but it is capable of doing ANYTHING as far as maps are concerned. Okay, maybe not anything, I admit it's above my skill level to use effectively. You can import data sets with it, effectively it's more of a map aggregation and editing tool. It's far more capable than OSM and you can work offline once the data sets are imported.

There's also Marble, not the same thing as the other suggestion I see commented. It's got a version for QT and GTK and some appimages out there. It's not as polished. In fact, it's kind of like MS Encarta Atlas, just not really modern. It has a bit of the 'old internet' feel to it, if that makes sense.

On android I can totally recommend organic maps

...if you're into paper books (and a hefty table) the DK complete world atlas includes a lot of geographic information, or if you prefer a dryer, more-authoritative presentation, the times world atlas is the grandaddy of the format...

...it looks like DK also offers a digital version of their previous editon...

(i have the millenium editions of both atlases, and they're both fantastic tomes, but i think the DK complete atlas is more of what you're looking for)

There's an app in Linux called "maps"

https://sourceforge.net/projects/viking/

Lol, I should learn to read +__+