Semager is a freely available semantic search engine out of Würzburg. The UI is a little lack-luster, for starters. But more importantly, I’m not convinced of the results–at least not based on the searches I tried.
A search for “usability,” for instance, exposes “testing” as the #1 related keyword. OK, that’s fine. But then they seem to be using those terms for further search processing (I’m guessing), so that the 5th and 6th results are about testing, but not usability testing.
And an ego-search for my name didn’t surface my book in the results or in the related terms, which had “pragmatism” as the first one. Oh well.