Cross-browser | Understanding and definition of the Cross-browser

Cross-browser refers to the ability for a website, web application, HTML construct or client-side script to support all the web browsers. The term cross-browser is often confused with multi-browser. Multi-browser is a new paradigm in web development that allows a website or web application to provide more functionality over several web browsers, while ensuring that the website or web application is accessible to the largest possible audience without any loss in performance. Cross-browser capability allows a website or web application to be properly rendered by all browsers. The term cross-browser have existed since the web development began.

The term is still in use, but to lesser extent. The main reasons for this are:
  1. Later versions of both Internet Explorer and Netscape included support for HTML 4.0 and CSS1, proprietary extensions were no longer required to accomplish many commonly desired designs.
  2. Somewhat more compatible DOM manipulation techniques became the preferred method for writing client-side scripts.
  3. The browser market has broadened, and to claim cross-browser compatibility, the website is nowadays expected to support browsers such as Mozilla Firefox, Opera,[Chrome] and Safari in addition to Internet Explorer and Netscape.
  4. There has been an attitude shift towards more compatibility in general. Thus, some degree of cross-browser support is expected and only its absence needs to be noted.
The history of cross-browser is involved with the history of the "browser wars" in the late 1990s between Netscape Navigator and Microsoft Internet Explorer as well as with that of JavaScript and JScript, the first scripting languages to be implemented in the web browsers. Netscape Navigator was the most widely used web browser at that time and Microsoft had licensed Mosaic to create Internet Explorer 1.0. New versions of Netscape Navigator and Internet Explorer were released at a rapid pace over the following few years. Due to the intense competition in the web browser market, the development of these browsers were fast-paced and new features were added without any coordination between vendors. The introduction of new features often took priority over bug fixes, resulting in unstable browsers, fickle web standards compliance, frequent crashes and many security holes.

he World Wide Web Consortium (W3C), founded in 1994 to promote open standards for the World Wide Web, pulled Netscape and Microsoft together with other companies to develop a standard for browser scripting languages called "ECMAScript". The first version of the standard was published in 1997. Subsequent releases of JavaScript and JScript would implement the ECMAScript standard for greater cross-browser compatibility. After the standardization of ECMAScript, W3C began work on the standardization of Document Object Model (DOM), which is a way of representing and interacting with objects in HTML, XHTML and XML documents. DOM Level 0 and DOM Level 1 were introduced in 1996 and 1997. Only limited supports of these were implemented by the browsers, as a result, non-conformant browsers such as Internet Explorer 4.x and Netscape 4.x were still widely used as late as 2000. DOM Standardization become popular since the introduction of DOM Level 2, which published in 2000. It introduced the "getElementById" function as well as an event model and support for XML namespaces and CSS. DOM Level 3, the current release of the DOM specification, published in April 2004, added support for XPath and keyboard event handling, as well as an interface for serializing documents as XML. By 2005, large parts of W3C DOM were well-supported by common ECMAScript-enabled browsers, including Microsoft Internet Explorer, Opera, Safari and Gecko-based browsers (like Firefox, SeaMonkey and Camino).