From the publishers website:
Hex Kit is a multi-platform, lightweight desktop application for quickly and effortlessly building hex maps for your table top role playing games. We've built this application to have an emphasis on tile variety, art, and usability at the table.
Variety: Hex Kit was built around the original Hex Kit Volume One: Fantasyland, a collection of over 1,100 hand-illustrate map tiles. In the original kit instead of having one tile per terrain style or icon type, there is dozens of illustrations for different categories. Rather than painting a desert by repeating the same dune tile, you can paint a desert with flat tiles, dune tiles, palm trees, and oases. You can even mix in plateaus, cacti, and briar patches from the badlands tile set. The desktop application will automatically paint a random assortment of tiles from each category without the user needing to pick the individual tiles.
Hex Kit also allows the you to cherry-pick, or select a range of tiles from categories to randomly paint. Also included are tools to flip, rotate, and layer tiles on top of one another for maximum variety. On top of the ability to create rich, varied maps you can also use the powerful, custom map generator to take what little hard work there is out of making maps.