The first web browser was:

Concept

A web browser is client software that retrieves and displays resources on the World Wide Web. Identifying the earliest browser requires distinguishing the browser program from the Web itself and comparing documented development dates.

Application

1. WorldWideWeb was created by Tim Berners-Lee at CERN in 1990. It was both a browser and an editor, and it was later renamed Nexus.

2. Netscape Navigator appeared in 1994, Internet Explorer in 1995, and Firefox in 2004. Each therefore came after the 1990 WorldWideWeb program.

3. In the source paper, the spaced option “World Wide Web” refers to the 1990 program WorldWideWeb, later renamed Nexus. On that intended reading, it is the earliest listed browser.

Contrast

• Internet Explorer was released in 1995, five years after WorldWideWeb.

• Netscape Navigator was released in 1994, four years after WorldWideWeb.

• Firefox was first released in 2004, much later than the other listed browsers.

• NCSA Mosaic appeared in 1993 and was an influential graphical browser that helped popularize the Web, but it post-dated the 1990 WorldWideWeb program. “First popular graphical browser” is different from “first web browser.”

Cross-check

CERN and W3C historical records separately identify WorldWideWeb as the first browser-editor. This also distinguishes the program from the World Wide Web information system.

Therefore, in the source paper’s wording, the answer is World Wide Web—the WorldWideWeb browser later named Nexus.