I used to read lot of science fiction around the this material was first published, but I don't remember George R.R. Martin from then. He's become better known since then I believe. Anyway this book is not bad, it's about a trader Tuf who acquires an ancient spaceship which allows him to become an ecological engineer. It's a bit far fetched because Tuf, who previously knew nothing on the subject, becomes one of the most powerful and knowledgeable ecological engineers in the galaxy and goes around solving ecological problems around the different star systems.
Even though it's set far in the future the characters in the books still seem to use 1980s technology and the book is already quite dated. It's not a bad read though, the format means you can right almost endless stories set to the basic format of Tuf going somewhere, solving a problem, and then leaving. I give the book 6 out of 10.
Next up is the final science fiction book.