Why browser compatibility?
The Hypertext Markup Language (HTML) — the language in which web pages are written — is rigorously controlled by internationally supported standards. The World Wide Web Consortium (W3C) is responsible for developing and issuing these specifications. Over the years, various standards have been issued, most notably HTML 2.0, 3.2, 4.0, and most recently, HTML 4.01. Each successive version adds more tags (the basic unit of hypertext markup) to increase functionality. Occasionally, older tags are depreciated, meaning that they may not be supported in future releases. Web browsers are supposed to ignore any markup tags that they don’t understand, thus insuring downlevel compatibility. However, browser manufacturers, in order to improve their product and stay competitive, often will include support for new tags not included in any W3C standard. This is not necessarily a bad thing, as it often drives improvements in later standards. As an example, the
