Yes, it's an experiment in internet publishing. LWE found that his publisher wanted him to concentrate on fiction set in places other than his well-known fantasy world of Ethshar. So he published it online, serially, and solicited donations to pay for his time. Apparently it was a success, as the book is now finished and, for the moment, is available online in it's entirety.
There have been eight Ethshar novels. They are great light fantasy. This one follows up on a loose end from an earlier work. A misenchanted mirror started spewing out small talking squeaky frog things (the spriggans of the title). About one every few minutes. Continuously. Eventually, as the supply of spriggans becomes an oversupply, this becomes a problem. People start thinking about how much spriggan weight the world-disc can carry. Our hero, Gresh, is assigned to locate and neutralize the aforesaid mirror.
There's not much character development here, it's pretty much a puzzle book dressed up with magic. It still manages to be engaging and fun. Recommended.