Short answers, pulled from the story.
Puella Magi Madoka Magica first aired on the 7th of January 2011. The broadcast was interrupted by the 2011 Tōhoku earthquake and tsunami, which caused the final two episodes to be delayed until April of the same year.
Gen Urobuchi wrote the screenplay for Puella Magi Madoka Magica. The series was created by the collective known as Magica Quartet and animated by the studio Shaft.
Magical girls in Puella Magi Madoka Magica give up their souls to form Soul Gems and turn into witches when their Soul Gems become too tainted with despair. This process transforms them from heroes into the very monsters they fight.
Homura Akemi repeats the same month countless times to save Madoka Kaname from a tragic fate. She is the only one who remembers the events of the previous timelines.
Each Blu-ray Disc volume of Puella Magi Madoka Magica sold more than 50,000 copies in Japan. The series was released on six Blu-ray Disc volumes between April 27 and the 21st of September 2011.