This license not applies to the graphic tiles, they are from CuddlyClover: Fantasy Hex Tiles.
This is a tiled version of this project: HTML5 Procedural Hexagon Terrain Genenerator
You can see the generator working at the Demo Page.
Check the original for the full list of features and references. This version added:
- Applied tiles for every biome (elevation / moisture).
- Rivers. Code for generation of the river's sources.
- A code to generate random numbers in advance.
- Fixed hexSize to adapt to the tileset size art.
- Code to generate lakes / swamps, volcanoes and also lairs.