Northwestern University:

Two annual productions are especially notable: the Waa-Mu show, and the Dolphin show. Waa-Mu is an original musical, written and produced almost entirely by students. Children's theater is represented on campus by Griffin's Tale and Purple Crayon Players. Its umbrella organizationthe Student Theatre Coalition, or StuCo, organizes nine student theatre companies, multiple performance groups and more than sixty independent productions each year. Many Northwestern alumni have used these productions as stepping stones to successful television and film careers. Chicago's Lookingglass Theatre Company, for example, which began life in the Great Room in Jones Residential College, was founded in 1988 by several alumni, including David Schwimmer; in 2011, it won the Regional Tony Award.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". Which theater company was founded by several Northwestern alumni in 1988?
Chicago's Lookingglass