100 Fastest-Growing rank: 4 (Previous rank: N.A.)
CEO: Robin Li
Address: 10 Shangdi 10th St., Beijing, China

Founded by Robin Li and Eric Xu in 2000, Baidu has evolved into the largest search engine portal in China with a market share of nearly 75%. Its services let more than 300 million Chinese users find news, web sites, audio files and images and targeted marketing tools like P4P, which lets companies pay for and generate ads that appear in search listings.

Recently, Baidu struck a two-year deal with One-Stop China, a local joint venture owned by Universal Music, Warner Music and Sony Music. It will let users legally download and stream over 500,000 songs for free. Aggressive moves such as these goes a long way to explaining why the search portal saw three-year annualized earnings-per-share growth of 78%.

By JP Mangalindan - Last updated September 12 2011: 10:49 AM ET