From http://www.w3schools.com (Copyright Refsnes Data)

W3C DOM Activities

The Document Object Model (DOM) is a platform and language neutral Application Programming Interface (API) that allows programs to access and update the content, structure, and style of a document.

DOM Tutorials

To learn more about the DOM, read our HTML DOM tutorial and our XML DOM tutorial.

DOM Level 0

The DOM Level 0 is not a W3C specification. It is just a definition of the functionality equivalent to that found in Netscape Navigator 3.0 and Microsoft Internet Explorer 3.0.

Key players in the development of the DOM has been people from ArborText, IBM, Inso EPS, JavaSoft, Microsoft, Netscape, Novell, the Object Management Group, SoftQuad, Sun Microsystems, and Texcel.

W3C's DOM Level 1 builds on DOM Level 0.

DOM Level 1

DOM Level 1 concentrates on HTML and XML document models. It contains functionality for document navigation and manipulation.

DOM Level 1 became a W3C Recommendation 1. October 1998. 

DOM Level 2

DOM Level 2 became a W3C Recommendations 13. November 2000:

DOM Level 2 adds a style object to the DOM, to manipulate the style information in a document.

DOM Level 2 also defines an event model and provides support for XML namespaces.

DOM Level 2 Core

DOM Level 2 Core specifies an API to access and update the content and structure of documents. The API also contains interfaces dedicated to XML.

DOM Level 2 HTML

DOM Level 2 HTML specifies an API to manipulate the structure and contents of an HTML document.

DOM Level 2 Views

DOM Level 2 Views specifies an API to dynamically access and update the view of a document. A view is an alternate representation/presentation of a document.

DOM Level 2 Style

DOM Level 2 Style specifies an API to dynamically access and update the content style sheets.

DOM Level 2 Events

DOM Level 2 Events specifies an API to access document events.

DOM Level 2 Traversal-Range

DOM Level 2 Traversal-Range specifies an API to dynamically traverse and identify a range of content in a document.

DOM Level 3

DOM Level 3 specifies content models (DTD and Schemas) and document validation. It also specifies document loading and saving, document views, document formatting, and key events.

DOM Level 3 Requirements

The DOM Requirements document was released as a Working Draft 12. April 2000. 

The following DOM Level 3 Working Drafts were released 1. September 2000:

DOM Level 3 Core

DOM Level 3 Core specifies an API to access and update the content, structure and style of documents.

DOM Level 3 Events

The DOM Level 3 Events API expands the functionality of the Level 2 Event API by adding new interfaces and new event sets.

DOM Level 3 Load and Save

DOM Level 3 Content Model specifies an API for document loading and saving, content models (DTD and Schemas) and document validation support.

DOM Level 3 Views and Formatting

DOM Level 3 Views specifies an API to dynamically access and update the view of a document. A view is an alternate representation/presentation of a document.

W3C DOM Specifications and Timeline

W3C Reference:

W3C DOM Home Page

From http://www.w3schools.com (Copyright Refsnes Data)