What does it take at the current stage of the Internet development to launch globally a new browser that has been written new from ground up? In addition to supporting up-to-date web standards such as XML, SOAP, XHTML, DOM, etc., and new script/encoding support such as Bidi scripts and GB 18030 encoding (with Unicode surrogate range support), browser developers need to ensure that existing web sites do not break on the newly developed browser.

Mozilla/Netscape 6 uses a new generation layout and parser engine called "Gecko". The Gecko engine is not an offshoot of the Communicator layout engine and behaves quite differently from the latter with regard to web standards. Its support for international standards are impressive and adheres to clear cut distinction between the standard mode and quirks modes based on the document's DOCTYPE. Almost none of private extensions developed during the version 4 days of Internet Explorer or Netscape Navigator are supported in the new engine.

This paper presents how Mozilla and Netscape have been dealing with the web standards and backward compatibility challenge around the globe. I will in particular focus on two public web site compatibility-testing projects we conducted in Japan and China with the help of volunteers in 2 countries. I will discuss in detail common web standards related problems found in these public testing projects and how we are approaching to resolve these issues with the web site developers.

The results of top site testing in Japan and those of China present a study in contrast reflecting the stages of the Internet development in each country. While the testing project is ongoing in China, the counterpart in Japan was completed in January of 2002 though volunteer evangelists continue to help web sites with the problems found during the testing phase. The project report in Japan generated considerable press among the online and print media.

This paper concludes with the benefits of conducting public site compatibility testing. They include 1) raising the awareness of W3C standards among the web developer community and public, 2) helping grow the number of web standards evangelists among volunteers, 3) helping a new browser get adopted and understood, and 4) what special problems are caused by the different scripts and encodings used in the 2 countries.