Zvon.org contains references for many XML‐related standards, including XHTML, MathML, XSLT, CSS, and SVG. The references contain functional examples, which could also be used as compliance tests.
The Mozilla standards compliance team has an exhaustive test suite for HTML, XHTML, XML, CSS, JavaScript, and DOM compliance. Not only does each attribute of each element have its own test page, sometimes there are separate pages for each value of each attribute.
An outstanding HTML and CSS test suite, with a database of results in different browsers. Includes torture tests for fine points like collapsing empty paragraphs, underline color different from text color, and setting styles on <html> and <head> elements.
Pete’s suite tests support for advanced HTML, XHTML, and XML markup, PNG images, integrated MathML and SVG, and useful Unicode typesetting, technical, and mathematical characters.
This downloadable automated performance test suite includes HTML 4.0, HTML 3.2, XML with CSS, and XML with XSL compliance tests, as well as tests for audio, video, and 3D file types.
Stress tests designed to push Mozilla’s endurance. Loads lists of pages for as long as the browser continues to run.
Tests for character sets, HTML 2.0, 3.2, and 4.01, JavaScript 1.0–1.5, and image and sound file formats.
Includes a suite of test pages covering the full range of Unicode 3.2 characters, and a information about Unicode support in fonts, Web browsers, and other software.
Table of browser support for various character entities.
Collection of graphic images designed to test support for the PNG standard.
Test suite for the various features of HTML 4.0’s <object> element, using many different content types.
Test for character entities.
Brief tests demonstrating iCab support of several HTML 4.0 features.
Since HTML is an application of SGML, HTML Web browsers technically should support SGML features like tag minimization (<em/example/). This officially dead
site tests this and other features of SGML syntax.
A simple page I made to test XHTML Basic served with various content types.
The official MathML 2.0 test suite by the standards body itself.
Demonstrations and tests of various WML features.
Tests for every aspect of the CSS2 specification. RichInStyle.com also has detailed documentation of CSS bugs in major browsers.
Official test suites by the CSS working group. The CSS level 1 test suite is comprehensive. There are also tests for Mobile Profile 1.0 and CSS level 3 selectors.
Prototype of an official CSS level 2 test suite for the W3C.
Detailed tests covering much of CSS level 2.
The Web site for his book, CSS 2: Feuilles de styles HTML, contains a CSS level 2 test suite, in French.
A tough but fair
composite test of the CSS‐1 box model as applied to HTML 4.0.
Downloadable set of 800 ECMAScript tests of DOM level 1 support, including the Fundamental, Extended and HTML features.
A fine book preaching the advantages and teaching the techniques of forward‐compatible standards‐based Web design.
Documentation of elements and attributes from HTML 2.0 through XHTML 1.1 (and proprietary ones too), with tables listing what versions of Internet Explorer, Mosaic, Netscape, and Opera support them.
I rely on their excellent online validation and link checking services, They have a useful and not overly technical HTML 4.0 reference, and articles on HTML style.
Yucca’s articles about Web authoring are recommended reading. The articles elsewhere on the Web that he recommends are also worthwhile.
Review of browsers that choose between quirky and more standards‐compliant modes based on the <!DOCTYPE> declaration of a Web page, listing many other resources on the subject.
Extensive list of documents related to the use of the underused <link> element. In English and German.
Mark’s weblog Dive Into Mark posted an essay about <object>, which linked to my object test page with the annotation, This shows just how incredibly broken IE/Win’s OBJECT handling is.
Over the next few days, other Web development blogs mentioned the story and also linked to my page. The cumulative effect was a surprising surge of hits to the object test page in particular and my test suite in general.
Your Web browser identified itself as Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com) when it requested this page. Mozilla 5.0
, why do you lie to me so?