Reading material on Gromov and his work is available here. Being unable to understand his technical work, I will limit myself to pointing out what people have said about him.
- "It is incredible what Mikhail Gromov can do, just with the triangle inequality." (Dennis Sullivan)
- "The works of Mikhail Gromov should be read until the pages fall off." (Marcel Berger)
Here is what the great man says about his opus:
The readers of my papers look only at corollaries, sometimes also at the technical tools of the proofs, but almost always never study them deeply enough in order to understand the underlying thought.
Does this mean that the "underlying thought" is carefully hidden in Gromov's papers? Shouldn't it be one of the author's duties in writing a paper to make the underlying thought apparent to the readers? What useful role can hiding the author's thoughts from the readers possibly have?
Anyway, we are surely in the presence of a giant of human thought, so kudos to him from a (hopefully) honest toiler.