Here is production information and a stellar collection of the early works of the canon of mid- t0 late 20th Century American playwrights: McNally, Lanford Wilson, Guare, Hoffman, Gurney, Maria Irenes Fornes, Ludlam, Amiri Baraka, Shepard, Rabe--and many lesser luminaries as well.
You might think I'm biased. I was there. I was part of it. Some of my plays are mentioned. I'm even writing my own book about that time.
There were several anthologies of plays from early Off-Off-Broadway published in the early seventies. Many of them had an agenda, i.e. abstract theatre, plays by writers in a certain group, gay plays, radical plays. The Off-Off-Broadway Book also had an agenda: to create an enduring record of that exciting time. I could argue with some of the choices included but the editors were right to opt for inclusion rather than exclusion. I could even gripe that a major play of mine went unmentioned (in a list compiled by a close friend) but I'm glad there's a record of everything else. And I'm glad there's a record of what everyone else did, even of the plays I didn't like, but especially of those I did like. There is a commentary on each of the theaters listed, and there are representative plays. There's a helluva lot of bang here for your buck, and it's a keeper.