Netscape Communications Corporation (originally Mosaic Communications Corporation) was an American independent computer services company with headquarters in Mountain View, California, and then Dulles, Virginia. Its Netscape web browser was once dominant but lost to Internet Explorer and other competitors in the so-called first browser war, with its market share falling from more than 90 percent in the mid-1990s to less than 1 percent in 2006. An early Netscape employee Brendan Eich created the JavaScript programming language, the most widely used language for client-side scripting of web pages and a founding engineer of Netscape Lou Montulli created HTTP cookies. The company also developed SSL which was used for securing online communications before its successor TLS took over.

Netscape stock traded from 1995 until 1999 when the company was acquired by AOL in a pooling-of-interests transaction ultimately worth US$10 billion. In February 1998, approximately one year prior to its acquisition by AOL, Netscape released the source code for its browser and created the Mozilla Organization to coordinate future development of its product. The Mozilla Organization rewrote the entire browser's source code based on the Gecko rendering engine, and all future Netscape releases were based on this rewritten code. When AOL scaled back its involvement with Mozilla Organization in the early 2000s, the Organization proceeded to establish the Mozilla Foundation in July 2003 to ensure its continued independence with financial and other assistance from AOL. The Gecko engine is used to power the Mozilla Foundation's Firefox browser.

Netscape's browser development continued until December 2007, when AOL announced that the company would stop supporting it by early 2008. As of 2011, AOL continued to use the Netscape brand to market a discount Internet service provider.