GMap.NET Windows Forms & Presentation is an excellent open source, powerful, free and cross-platform .NET control. Allows the use of routing, geocoding, directions and maps from Google, Yahoo!, Bing, OpenStreetMap, ArcGIS, Pergo, SigPac, Yendux, Mapy.cz, Maps.lt, iKarte.lv, NearMap, HereMap, CloudMade, WikiMapia, MapQuest and many more.
I have checked out and updated the project to .net6.0 without any issues.
The latest nuget package does not support .net 6 even though the release notes claim that it does. (Application using net6.0-windows10.0.22000.0)