30 Rock is an American television comedy series created by Tina Fey that airs on NBC. The series is largely based on Fey's experiences as head writer for Saturday Night Live. 30 Rock takes place behind the scenes of a fictional live sketch comedy series depicted as airing on NBC; the name "30 Rock" refers to the address of the GE Building where NBC Studios is located, 30 Rockefeller Plaza. This series is produced by Broadway Video and Little Stranger, Inc., in association with NBC Universal.

Source: Wikipedia.org