Complex sentence: Its host was and still is James Lipton, Dean Emeritus of the Actors Studio Drama School; it provides in-depth interviews with actors, directors, writers, and other artists, some but not all of whom are members of the Studio.
Split into simpler sentences: Its host was and still is James Lipton, Dean Emeritus of the Actors Studio Drama School. The program provides in-depth interviews with actors, directors, writers, and other artists, some but not all of whom are members of the Studio.