Welcome to the Guild Eon.

Ask a question, get a dozen answers.

First, FM8 is Fractal Mapper 8, Mark knows much more about it than I do.

Dundjinni is a great mapping program that lets you draw floors and walls using tile brushes and then stamp on objects and covers. One of it's strengths is that the objects can be moved, resized and rotated at anytime. While it does not create objects, we have a library of 75,000 objects and textures freely available on the DJ Forums, and they can be used in most mapping and art programs as they are mostly .png files.
The downside to Dundjinni is that it was originally written for Windows XP / Java in 2003. That caused a lot of problems when Vista came out, so Version 1.0.7 was made available in 2008. Every new generation of Windows makes it harder to install DJ.
The other problem is that the owner disappeared 2 years ago, and the webstore is malfunctioning and can't be fixed without her. The only way to purchase DundJinni is the occasional copy that shows up on Amazon or Ebay. I love the program, but would not recommend it for someone just getting started.
For the sake of full disclosure, I am one of the Administrators on the Dundjinni Forums.