[10] In 1990, Tim Berners-Lee had already written the first browser, WorldWideWeb (later renamed to Nexus), but that program only worked on the proprietary software of NeXT computers, which were in limited use.

[7] Berners-Lee and his team could not port the WorldWideWeb application with its features—including the graphical WYSIWYG editor— to the more widely deployed X Window System, since they had no experience in programming it.

[11] The team recruited Nicola Pellow, a math student intern working at CERN,[12] to write a "passive browser" so basic that it could run on most computers of that time.

[1] The main developer, Pellow, started working on the MacWWW project, and both browsers began to share some source code.

[24] In the May 1993 World Wide Web Newsletter Berners-Lee announced that the browser was released into the public domain to reduce the work on new clients.

This was considered to be unfortunate by Robert Cailliau, one of the developers: "I think in retrospect the biggest mistake made in the whole project was the public release of the Line-Mode Browser.

It gave the Internet hackers immediate access, but only from the point of view of the passive browser—no editing capabilities"[11]The Line Mode Browser was designed to be able to be platform independent.

There are official ports to Apollo/Domain,[33] IBM RS6000,[33] DECStation/ultrix,[33] VAX/VMS,[33] VAX/Ultrix,[33] MS-DOS,[13] Unix,[13][34] Windows,[34] Classic Mac OS,[34] Linux,[34] MVS,[35] VM/CMS,[35] FreeBSD,[36] Solaris,[36] and to macOS.

[1][17][37] Other features included rlogin[17] and telnet[17] hyperlinks, Cyrillic support (added on 25 November 1994 in version 2.15),[1] and ability to be set up as a proxy client.

[29] The Line Mode Browser has had problems recognizing character entities, properly collapsing whitespace, and supporting tables and frames.