Automatic Heightmap Generation?

Quick question,

If you do not want to develop a heightmap from scratch. Is it possible to use heightmaps generated in programs such as Terragen, VUE D’ espirit, etc.

**If I am using the wrong terminology I apologize since I am new to this.

Also if the above is possible, where are best resources to look for such info. I have searched the web but not sure how I should search for the information.

Thanks

No comprende:

Do you want to create automatically generated heightmaps yourself (easy)?

OR

Do you want to load and use some other programs automatically generated heightmaps?
(hard)