Complex sentence: Derby Playhouse was a theatre production company based in Derby, England and the former name of the theatre which it owned and operated from its opening in 1975 until 2008, when the company ceased operating after a period in administration.
Split into simpler sentences: Derby Playhouse was a theatre production company based in Derby, England and the former name of the theatre in which they performed. The theatre was owned and operated by Derby Playhouse Ltd from its opening in 1975 until 2008, when the company ceased operating after a period in administration.