The author of the blog A Character for Every Game has posted 17 sets of dungeon geomorphs for people to use to organically create dungeons with reusable tiles. It's very nice - I'm using it for my next One-Page Dungeon submission. Hexographer has a free version which lets you make simple hex-grid area maps for free.
As far as freeware goes, you have some options. I assume you'd like to actually make your own maps and can't afford to use the stuff above. There are several cartographers who post maps or map samples online (i.e., Paratime Design Cartography) some of these maps are produced with Dundjinni and CC3, and both have galleries where users post their own maps. I own both, and they're very nice for what they do: CC3 is basically a stripped-down CAD program, while Dundjinni uses tiles, but they produce nice results and have a lot of support.
The two heaviest hitters in the RPG map-making software industry (it's an industry?!?) are Campaign Cartographer 3 and Dundjinni. There are several options for map-making software.
Re: Open Source or Free Map Making Software
