The not-for-profit companies on the East Coast that have had the most success developing new works for Broadway are in New York City:
The Public
-- Hair
-- A Chorus Line
-- Pirates of Penzance
-- Caroline, or Change
-- Topdog/Underdog
-- Elaine Stritch At Liberty
-- Bring in Da Noise, Bring in Da Funk
-- Two Gentlemen of Verona
-- Angels in America
-- Well
-- Take Me Out
-- The Wild Party
-- On The Town
-- Plenty
-- The Mystery of Edwin Drood
-- For Colored Girls
-- Streamers
-- The Basic Training of Pavlo Hummel
-- Sticks and Bones
and several others
Playwrights Horizons
-- Grey Gardens
-- I Am My Own Wife
-- The Dead
-- Once on the is Island
-- Assassins
-- The Heidi Chronicles
-- Sunday in the Park with George
Second Stage
-- Spelling Bee
-- The Little Dog Laughed
The Vineyard
-- Avenue Q
Plus Roundabout, MTC and Lincoln Center have developed dozens of new works for Broadway that have played in their Tony-eligible Broadway spaces (American Airlines Theater, Studio 54, The Biltmore and the Vivian Beaumont).
"What a story........ everything but the bloodhounds snappin' at her rear end." -- Birdie
[http://margochanning.broadwayworld.com/]
"The Devil Be Hittin' Me" -- Whitney