W3C recently announced the release of Unicorn, a one-stop tool to help people improve the quality of their Web pages. Unicorn combines a number of popular tools from W3C in a single, easy interface, including the Markup validator, CSS validator, mobileOk checker, and Feed validator, which remain available as individual services as well.

This is a simple but important improvement to the W3C service. It enables anyone to very quickly and easily check individual web pages to see if they are coded correctly. This is an essential step before checking a page for accessibility; if the page is not well coded it by definition will fail the Web Content Accessibility Guidelines (WCAG 1 or 2), and as important bad coding may make it impossible for assistive technology to render the page correctly.

There are a variety of commercial products available that are designed to provide the equivalent compliance testing and other tests not provided by Unicorn, so when should you use Unicorn?

• Unicorn is free and if it provides all the facilities you need that must be an advantage. Its major limitation is that it will only check one page at a time so cannot be used to check the whole of an existing website or large numbers of new pages.
• It is developed by the same organisation that developed the standards and guidelines so I believe that the results of the tests should be definitive and therefore can be used as a verification of the results of the commercial products.
• It is a very useful tool when you have found a page that does not seem to be behaving correctly. Running Unicorn against it is a quick way to start analysing the problem.
• Its support of MobileOK is a feature not yet supported by all the commercial products. The increased use of the Web on mobiles means that these tests are increasingly important.

Having expounded the benefits of Unicorn I need to emphasise that it cannot remove the need for a commercial product as an integral part of the development of Internet and Intranet sites. It should be seen as an adjunct to the commercial products.

The following paragraph is a direct quote from the W3C website which I pass on to my readers for information:

W3C invites developers to enhance the service by creating new modules and testing them in our online developer space (or installing Unicorn locally). W3C looks forward to code contributions from the community as well as suggestions for new features. W3C would like to thank the many people whose work has led up to this first release of Unicorn. This includes developers who started and improved the tool over the past few years, users who have provided feedback, translators who have helped localize the interface with 21 translations so far, and sponsors HP and Mozilla and other individual donors. W3C welcomes feedback and donations so that W3C can continue to expand this free service to the community. Learn more about W3C open source software.