Mozilla Composer is the former free and open-source HTML editor and web authoring module of the Mozilla Application Suite (the predecessor to SeaMonkey). It was used to create and to edit web pages, e-mail, and text documents, and available for Windows, macOS and Linux. Composer was a graphical WYSIWYG HTML editor to view, write and edit HTML source code.

In September 2008 Daniel Glazman announced a new WYSIWYG HTML editor, BlueGriffon, written from scratch and based on Mozilla Gecko and XULRunner.

SeaMonkey, the community-driven successor to Mozilla Suite, includes an HTML editor named Composer that is developed from the Mozilla Composer code contained in the original Mozilla Suite. based on Mozilla Composer. It is intended to be an open-source alternative to proprietary software like Microsoft Expression Web and Adobe Dreamweaver. As a WYSIWYG editor, it is designed to be easy for novice users, and does not require any knowledge of HTML or CSS to use. It runs on Mac OS X, Windows and Linux and incorporates Cascading Style Sheets support and other improvements from software company Disruptive Innovations. Nvu was the brainchild of Kevin Carmony, CEO for Linspire, who wanted an easy-to-use, WYSIWYG HTML editor for Linux users. Under Carmony's direction, Linspire started and sponsored Nvu, hiring Daniel Glazman, former Netscape Communications Corporation employee, to be the lead developer. KompoZer was forked as a community-driven project with development coordinated through SourceForge.

KompoZer's WYSIWYG editing capabilities are one of the main attractions of the software. In addition, KompoZer allows direct code editing as well as a split code-graphic view.

The most recent version is KompoZer 0.8 beta 3, released February 2010, using Gecko 1.8.1. The stable version was 0.7.10, released in August 2007. The only regular developer said in June 2011 that development "is stalled at the moment".

As a 32-bit application, it is no longer supported on macOS Catalina and later versions.

Standards compliance

KompoZer complies with the W3C's web standards. By default, pages are created in accordance to HTML 4.01 Strict and use Cascading Style Sheets (CSS) for styling, but the user can change the settings and choose between:

  • Strict and transitional DTD's
  • HTML 4.01 and XHTML 1.0
  • CSS styling or the old <code>&lt;font&gt;</code> based styling.

The application can call on the W3C HTML validator, which uploads pages to the W3C Markup Validation Service and checks for compliance.

See also

  • Comparison of HTML editors
  • ActiveState Komodo
  • BlueGriffon (replaces Nvu)
  • SeaMonkey (includes the Gecko-based HTML editor that KompoZer derived from)
  • List of HTML editors

References

  • Seamonkey Project
  • Daniel Glazman's BlueGriffon replacement for Mozilla Editor/Composer and NVU/KompoZer
  • Daniel Glazman about KompoZer and the new composer
  • nvu
  • Extensions and themes
  • Archive of official KompoZer website
  • Project website on SourceForge
  • Alternative project website with downloads and information
  • Development and User Forums
  • KompoZer and Nvu User Guide Contributed by Charles Cooke
  • Gin Up A Quick Web Page With Kompozer