Can someone give me some info on Asana?

Tweet

Have you heard of Asana, the task management for team work? This website is launched by one of the co - founder of facebook, Dustin Moskovitz for people to work on the same project of anything, to collaborate people in a team to accomplish a project. I still have some fuzzy idea about it after I watch the introductory video. So, does anyone ever participate this asana.com, and can you give me some info about it, what it really about? was it just an app or something else?