I recently asked a similar question on quora.com. Most of the answers weren’t very interesting to me, but one was. It’s here.
Still working on the Underworld. I’ve added cave-ins, jammed doors, and doors that ask you riddles. Next up, secret doors.
I just finished another section of My Name Is John Carter, so I should have more time to work on this for a while [edit: and just after I wrote that, I got a big editing job].
This twitter account apparently posts a randomly-generated fantasy map every hour (click the picture to go there).
There’s an article here about how they’re made.
I’ve added a few extras to Gigacrawler, such as a calendar and time limit, and some rules options such as OD&D, Basic or AD&D Hit Dice, ascending or descending Armor Class, and some options in selecting spells.
I’ve finished the code to generate the room layout of the Underworld.