Both praised and reviled as a laboratory of contemporary art, the Whitney has garnered much less attention for its permanent collection. A recent gift of 86 works by 23 artists promises to change that. AbEx pioneers Clyfford Still and Franz Kline join Pop-art greats Andy Warhol and Claes Oldenburg. And with Cy Twombly's sculptures, a 1954 Mark Rothko, and Jasper Johns's monotype series of a paintbrush-filled Savarin coffee can, the Whitney's repository of modern masters finally places the museum on a par with MOMA and the Guggenheim. The new acquisitions are on view in New York from October 24 until January 26. Also in the works is an addition to the museum's classic Marcel Breuer building—by none other than Rem Koolhaas.