Mozilla Composer is the
free and open-source
Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...
HTML editor
An HTML editor is a program for editing HTML, the markup of a web page. Although the HTML markup in a web page can be controlled with any text editor, specialized HTML editors can offer convenience and added functionality. For example, many HT ...
and web authoring module of the
Mozilla Application Suite
The Mozilla Application Suite (originally known as Mozilla, marketed as the Mozilla Suite) is a discontinued cross-platform integrated Internet suite. Its development was initiated by Netscape Communications Corporation, before their acquisition ...
(the predecessor to
SeaMonkey
SeaMonkey is a free and open-source Internet suite. It is the continuation of the former Mozilla Application Suite, based on the same source code, which itself grew out of Netscape Communicator and formed the base of Netscape 6 and Netsca ...
). It is used to create and to edit
web pages,
e-mail
Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" mean ...
, and text documents easily. It is compatible with
Windows
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ...
,
macOS
macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac (computer), Mac computers. Within the market of ...
and
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which i ...
. Composer is a
graphical WYSIWYG
In computing, WYSIWYG ( ), an acronym for What You See Is What You Get, is a system in which editing software allows content to be edited in a form that resembles its appearance when printed or displayed as a finished product, such as a printed d ...
HTML editor
An HTML editor is a program for editing HTML, the markup of a web page. Although the HTML markup in a web page can be controlled with any text editor, specialized HTML editors can offer convenience and added functionality. For example, many HT ...
. One also can view, write and edit
HTML
The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScri ...
source code with Composer.
[The SeaMonkey® Project](_blank)
Seamonkey-project.org. Retrieved on 2013-07-17.
In September 2008 Daniel Glazman announced a new WYSIWYG HTML editor,
BlueGriffon, written from scratch and based on Mozilla
Gecko
Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from .
Geckos ar ...
and
XULRunner
XULRunner is a discontinued, packaged version of the Mozilla platform to enable standalone desktop application development using XUL, developed by Mozilla. It replaced the ''Gecko Runtime Environment'', a stalled project with a similar purpose. ...
.
SeaMonkey
SeaMonkey is a free and open-source Internet suite. It is the continuation of the former Mozilla Application Suite, based on the same source code, which itself grew out of Netscape Communicator and formed the base of Netscape 6 and Netsca ...
, 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.
Nvu
Nvu (pronounced ''"N-view"'') is a
WYSIWYG
In computing, WYSIWYG ( ), an acronym for What You See Is What You Get, is a system in which editing software allows content to be edited in a form that resembles its appearance when printed or displayed as a finished product, such as a printed d ...
HTML editor
An HTML editor is a program for editing HTML, the markup of a web page. Although the HTML markup in a web page can be controlled with any text editor, specialized HTML editors can offer convenience and added functionality. For example, many HT ...
, based on Mozilla Composer. It is intended to be an
open-source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...
alternative to
proprietary software
Proprietary software is computer software, software that is deemed within the free and open-source software to be non-free because its creator, publisher, or other rightsholder or rightsholder partner exercises a legal monopoly afforded by modern ...
like
Microsoft Expression Web and
Adobe Dreamweaver
Adobe Dreamweaver is a proprietary web development tool from Adobe Inc. It was created by Macromedia in 1997 and developed by them until Macromedia was acquired by Adobe Systems in 2005.
Adobe Dreamweaver is available for the macOS and Windows ...
. As a WYSIWYG editor, it is designed to be easy for novice users, and does not require any knowledge of
HTML
The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScri ...
or
CSS
Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML or XML (including XML dialects such as SVG, MathML or XHTML). CSS is a cornerstone t ...
to use. It runs on
Mac OS X
macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lapt ...
,
Windows
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ...
and
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which i ...
and incorporates
Cascading Style Sheet
Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML or XML (including XML dialects such as SVG, MathML or XHTML). CSS is a cornerstone technol ...
s 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
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 on ...
employee, to be the lead developer.
Development
The original plan in June 2005 was to merge back the numerous changes into Mozilla Composer's source code tree. Since then the Mozilla Suite has been discontinued (then reintroduced as
SeaMonkey
SeaMonkey is a free and open-source Internet suite. It is the continuation of the former Mozilla Application Suite, based on the same source code, which itself grew out of Netscape Communicator and formed the base of Netscape 6 and Netsca ...
), and no one has merged the Nvu code back into Composer.
Standards compliance

Nvu complies with the
W3C's web standards. By default, pages are created in accordance to HTML 4.01 Transitional and use CSS for styling, but the user can change the settings and choose between:
* Strict and transitional
DTD's
*
HTML
The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScri ...
4.01 and
XHTML
Extensible HyperText Markup Language (XHTML) is part of the family of XML markup languages. It mirrors or extends versions of the widely used HyperText Markup Language (HTML), the language in which Web pages are formulated.
While HTML, prior ...
1.0
* CSS styling or the old
<font>
based styling.
The application includes a built-in
HTML validator
A validator is a computer program used to check the validity or syntactical correctness of a fragment of code or document. The term is commonly used in the context of validating HTML,Tittel, Ed, and Mary C. Burmeister. HTML 4 for Dummies. --For du ...
, which uploads pages to the
W3C's HTML Validator
The Markup Validation Service is a validator by the World Wide Web Consortium (W3C) that allows Internet users to check pre-HTML5 HTML and XHTML documents for Well-formed element, well-formed markup against a document type definition. Markup val ...
and checks for compliance.
Release history
* 0.1 was released on February 4, 2004
* 0.20 was released on March 25, 2004
* 0.3 was released on June 11, 2004
* 0.4 was released on August 10, 2004
* 0.5 was released on October 6, 2004
* 0.6 (1.0b) was pre-released on November 26, 2004
* 0.7 (1.0b2) was pre-released on January 6, 2005
* 0.8 (1.0b3) was pre-released on February 2, 2005
* 0.81 was pre-released on February 9, 2005
* 0.90RC1 was released on March 4, 2005
* 0.90 was released on March 11, 2005
* 1.0PR was released on April 5, 2005
* 1.0 was released on June 28, 2005
Shift to KompoZer
Daniel Glazman, the lead developer of
Nvu
Mozilla Composer is the free and open-source HTML editor and web authoring module of the Mozilla Application Suite (the predecessor to SeaMonkey). It is used to create and to edit web pages, e-mail, and text documents easily. It is compatible wi ...
, announced on September 15, 2006, that he had stopped official development on Nvu and that he was developing a successor as a
Mozilla.org
The Mozilla Foundation (stylized as moz://a) is an American non-profit organization that exists to support and collectively lead the open source Mozilla project. Founded in July 2003, the organization sets the policies that govern development, ...
project. It is written from scratch and based on Mozilla trunk
Gecko 1.9 and
XULRunner
XULRunner is a discontinued, packaged version of the Mozilla platform to enable standalone desktop application development using XUL, developed by Mozilla. It replaced the ''Gecko Runtime Environment'', a stalled project with a similar purpose. ...
.
PHP
PHP is a General-purpose programming language, general-purpose scripting language geared toward web development. It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. The PHP reference implementati ...
and
CSS
Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML or XML (including XML dialects such as SVG, MathML or XHTML). CSS is a cornerstone t ...
would be supported. A community-driven fork,
KompoZer
Mozilla Composer is the free and open-source HTML editor and web authoring module of the Mozilla Application Suite (the predecessor to SeaMonkey). It is used to create and to edit web pages, e-mail, and text documents easily. It is compatible w ...
, maintains Nvu codebase and fixes bugs until a successor to Nvu is released. Glazman's project is called
BlueGriffon.
KompoZer
KompoZer is a discontinued
open source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...
WYSIWYG
In computing, WYSIWYG ( ), an acronym for What You See Is What You Get, is a system in which editing software allows content to be edited in a form that resembles its appearance when printed or displayed as a finished product, such as a printed d ...
HTML editor based on the Nvu.
KompoZer was
forked as a community-driven project with development coordinated through
SourceForge
SourceForge is a web service that offers software consumers a centralized online location to control and manage open-source software projects and research business software. It provides source code repository hosting, bug tracking, mirrori ...
.
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
Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from .
Geckos ar ...
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".
[One Year At INRIA - Kaz'hack](_blank)
Kazhack.org. Retrieved on 2013-07-17.
As a
32-bit
In computer architecture, 32-bit computing refers to computer systems with a processor, memory, and other major system components that operate on data in 32- bit units. Compared to smaller bit widths, 32-bit computers can perform large calcula ...
application, it is no longer supported on
macOS Catalina
macOS Catalina (version 10.15) is the sixteenth major release of macOS, Apple Inc.'s desktop operating system for Macintosh computers. It is the successor to macOS Mojave and was announced at WWDC 2019 on June 3, 2019 and released to the p ...
and later versions.
Standards compliance
KompoZer complies with the
W3C
The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 and led by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working t ...
's web standards. By default, pages are created in accordance to
HTML
The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScri ...
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
Extensible HyperText Markup Language (XHTML) is part of the family of XML markup languages. It mirrors or extends versions of the widely used HyperText Markup Language (HTML), the language in which Web pages are formulated.
While HTML, prior ...
1.0
* CSS styling or the old
<font>
based styling.
The application can call on the W3C
HTML validator
A validator is a computer program used to check the validity or syntactical correctness of a fragment of code or document. The term is commonly used in the context of validating HTML,Tittel, Ed, and Mary C. Burmeister. HTML 4 for Dummies. --For du ...
, which uploads pages to the
W3C Markup Validation Service
The Markup Validation Service is a validator by the World Wide Web Consortium (W3C) that allows Internet users to check pre-HTML5 HTML and XHTML documents for well-formed markup against a document type definition. Markup validation is an impor ...
and checks for compliance.
See also
*
Comparison of HTML editors
The following tables compare general and technical information for a number of HTML editors.
Please see the individual products' articles for further information, comparison of text editors
This article provides basic comparisons for notable te ...
*
ActiveState Komodo
Komodo Edit is a free and open source text editor for dynamic programming languages. It was introduced in January 2007 to complement ActiveState's commercial Komodo IDE. As of version 4.3, Komodo Edit is built atop the Open Komodo project. Komodo ...
*
BlueGriffon (replaces Nvu)
*
SeaMonkey
SeaMonkey is a free and open-source Internet suite. It is the continuation of the former Mozilla Application Suite, based on the same source code, which itself grew out of Netscape Communicator and formed the base of Netscape 6 and Netsca ...
(includes the Gecko-based HTML editor that KompoZer derived from)
*
List of HTML editors
References
External links
Seamonkey ProjectDaniel Glazman's BlueGriffon replacement for Mozilla Editor/Composer and NVU/KompoZerDaniel Glazman about KompoZer and the new composernvu*
Extensions and themesOfficial KompoZer website*
Project website on SourceForge*
Development and User Forums*
*
Gin Up A Quick Web Page With Kompozer
{{FLOSS
Mozilla Application Suite
Free HTML editors