Is there any landscape renderer?

A landscape in Retrosia. Made with the landscape renderer 'Vista Pro'  (DOS). An old picture.

Are there any tools like that nowadays? Maybe something for Linux? Any suggestions?

Old map of my first fantasy world

 

Just to take a look. An old map of a fantasy continent that I once created. The name wasn't Retrosia, it had the working title 'Askalon' until I found out that there is a city that has this name. Made for a campaign but never really used. I take this as an inspiration for the new world. But the new one should have more sea and islands because sailing and seafights will be an important part of the rules. Maybe I can break this continent in into pieces?