The World Alamanac of Islamism is a new site by The American Foreign Policy Council, devoted to mapping out the various Islamist movements around the world. They have a section on Europe, with details on different countries.
From their main Europe page:
Buoyed by steady immigration from the Middle East and North Africa, as well as negative native demographics among continental states, the Muslim communities in Europe are becoming larger, more complex and more vocal. Within these communities, the past year saw Islamism continue to grow in strength as a political phenomenon.
The dominant mode of Islamist activism in Europe remains to operated within the parameters of existing political systems. Some groups, such as the Union of the Islamic Communities and Organizations of Italy, confine themselves to expanding the participation of Muslims in national politics, while others, like the Muslim Association of Britain, work to promote Islamist political thought, as well as the message and appeal of foreign Islamist groups such as the Muslim Brotherhood. Only a small minority—exemplified by England’s al-Muhajiroon, among other fringe elements—has advocated violence against, and the overthrow of, European governments. Those elements are closely monitored and proscribed by the authorities in question.
(source)