Tim Berners-Lee who invented the World Wide Web in 1990, did so by writing a web browser for the NeXTStep operating system. The original "WorldWideWeb" browser program had a graphical user interface and so on and is definitely recognizable to most people as a web browser. However, WorldWideWeb did not support graphics embedded in pages when it was first released. You can learn more about the original "WorldWideWeb" browser from Tim Berners-Lee himself.
The first web browser to become truly popular and capture the imagination of the public was NCSA Mosaic. Developed by Marc Andreessen, Jamie Zawinski and others who later went on to create the Netscape browser, NCSA Mosaic was the first to be available for Microsoft Windows, the Macintosh, and the Unix X Window System, which made it possible to bring the web to the average user. The first version appeared in March 1993. The "inline images," such as the boutell.com logo at the top of this page, that are an integral part of almost every web page today were introduced by NCSA Mosaic 2.0, in January of 1994. Mosaic 2.0 also introduced forms.

Netscape is the browser that introduced most all of the remaining major features that define a web browser as we know it. The first version of Netscape appeared in October 1994 under the code name "Mozilla." Netscape 1.0's early beta versions introduced the "progressive rendering" of pages and images, meaning that the page begins to appear and the text can be read even before all of the text and/or images have been completely downloaded. Version 1.1, in March 1995, introduced HTML tables, which are now used in the vast majority of web pages to provide page layout. Version 2.0, in October 1995, introduced frames, Java applets, and JavaScript. Version 2.0 was the last version of Netscape to introduce a major feature of the web as we know it today; later versions improved reliability and stability and introduced features that did not catch on as standards for all browsers. In 1998, Netscape decided to release their browser source code as open source software, and the Mozilla project began.

Microsoft Internet Explorer is by far the most common web browser in use as of this writing. Internet Explorer 1.0, released in August 1995, broke no important new ground in a way that became part of a future standard. Later versions of Internet Explorer quickly caught up; Internet Explorer 3.0 was very close to Netscape 2.0's feature set. In July 1996, Internet Explorer 3.0 beta introduced the first useful implementation of cascading style sheets, which allow better control of the exact appearance of web pages. In April 1997, Internet Explorer 4.0 introduced the first quality implementation of the Document Object Model (DOM), which allows Javascript to modify the appearance and content of a web page after it has been loaded.