The longest common substring problem (LCS) can be solved in O(n^2) time using dynamic programming, not O(n^3) as is stated by the author of that post. If the author is unable to get the basic fact right, I can hardly trust his benchmark. Also, I question the author's skill in C/C++: in my experiences, C is consistently faster than Java for such tasks and C++ is nearly as fast as C as long as we use it the right way. If we look at the computer benchmark games, OCaml never beats C in terms of speed. I doubt the conclusion was much different in 2006. The author should released the source code; otherwise the benchmark tells us nothing but his incapability in programming.

EDIT: in his comments to another commenter, the author was saying this: "[The OCaml compiler] could do some dramatic code rewriting that made it possible to merge loops, and hoist some local constants out of the restructured merged loop." A good C programmer should be able to do all the above simply by instinct. The author was not good enough. I buy the argument that being really good at C/C++ is more difficult than at other languages, but this is not the same thing as arguing C is inefficient.