The Democratic Alliance (DA) is a liberal South African political party, and the official opposition to the ruling African National Congress. It was formed when the Democratic Party entered into a short-lived alliance with the New National Party in 2000.
The present leader of the Democratic Alliance is Cape Town mayor Helen Zille, who took over from Tony Leon in May 2006. Zille, the World Mayor of the Year in 2008, opted against moving to the National Assembly, so the party is instead led in parliament by Celia-Sandra Botha. In January 2009, Botha announced her decision to leave party politics; her successor has not yet been chosen. The Democratic Alliance's chairperson is Joe Seremane, and the party's CEO is Ryan Coetzee.
Source: http://en.wikipedia.org