Post 200 The 2011 guide to the region's top businesses

Carlyle Group founders William Conway, Daniel D'Aniello and David Rubenstein. (Astrid Riecken/For The Washington Post)

Private companies

Carlyle Group

After 25 years as a private company, District-based Carlyle Group is preparing to go public sometime in the the first half of 2012. Though it cut its teeth in defense and aerospace deals, Carlyle now boasts a diversified portfolio, including real estate, a variety of companies, and esoteric assets such as the debt of foreign nations. One of its companies, Dunkin' Donuts went public in 2011. Co-founders William E. Conway Jr., David M. Rubenstein and Daniel A. D’Aniello are billionaires and beginning to give away substantial sums.

Trivia

Co-founder David M. Rubenstein is the largest single donor in Kennedy Center history, with gifts totaling over $25 million.