Math teachers of all sorts, from novice to master, men and women, teaching mathematics from K to college. The one commonality that all share is a passion for mathematics teaching.
A plethora of great math resources are available. The overwhelming majority have Creative Commons (CC) license as the authors want to give people the right to share, use, and build upon a work that they have created.
Perhaps never before in the history of education have teachers faced a greater set of challenges from Common Core to teacher evaluation to new asessments. These challenges require teachers to be more politically active and informed.