Muslim countries were a relative center of culture, learning and science for a few centuries after Islam was fairly well established. Their mathematical and medical contributions alone were pretty impressive (look where we get the words "algebra" and "cipher"). Translations of many Muslim works were used as university textbooks in Europe well into the middle of the last millennium, hundreds of years after they were first written. In contrast, at the time Europe/Christianity was just getting into its dark ages, producing practically nothing.
On the other hand, Muslim contributions seem to have tapered off to pretty much nothing after the 13th century.