What exactly are the attacks in Norway about?

I have read several articles on the tragedy in Norway at this point, but I am still very unclear as to why the attacks happened. The most I have been able to gather thus far is that the main suspect is an extreme rightist. The articles give no suggestion of a specific motive and state that the suspect never gave any indication of intent to act violently in the past. Am I missing something, or is this information simply not available yet? Enlighten me, please!