This is a catch-all term for a number of books and short stories by Sharon Lee and Steve Miller.
I don't know if the both co-wrote all of them or some of the books were done singling and some jointly or what, but...

Has anyone else encountered any?

What do you think of them?

The current publisher is offering some of their works free in ebook format (I suspect to drive sales of the physical copies), so here's a link to where you can check it out:
http://www.baen.com/agent-of-change.html