Evgeniya Trofimova, one of my bachelor students at University of Tartu, recently defended her thesis on "Compatibility Evaluation of Mainstream Internet Browsers with Respect to JavaScript Usage in Major Internet Sites".

The study was based on usage details of specific JavaScript language constructs at a selection of Web sites from Alexa Top 500 list of most popular Web sites. The JavaScript constructs were extracted from the Web sites and were then analyzed with respect to the compatibility master table available at http://www.quirksmode.org/compatibility.html. The study shows that Safari 4.0 for Windows, followed by Chrome 4, clearly outperforms other browsers with respect to JavaScript compatibility.

The following figure shows the ranking of mainstream browsers with respect to their ability to interpret JavaScript constructs, which are most commonly used in major Web sites.




An excerpt of the thesis follows.

According to the latest statistics (http://www.internetworldstats.com/stats.htm) about 26% of the World population uses the Internet. It means that the Internet has become an essential part of our everyday life and Internet applications must be reliable to support the provision of needed information. Mainstream Web pages are implemented by using standards, technologies and programming languages such as HTML, CSS and JavaScript. While the former two are used mainly for structuring and designing the layout of Web pages, the latter is widely applied for enhancing Web application functionality and interactivity. Although in general JavaScript has never been supported by modern browsers as widely as today, there are still some fragments of JavaScript which are interpreted differently between browsers. Furthermore, the large variety of available browsers has led to a situation where application developers either have to carefully select the target browsers for their Web applications or invest more time into testing and developing those applications.