Migrating and Application Compatibility
Migrating to a new operating system can pose certain unique challenges, especially with the need to support legacy web applications. In particular, if your organization relies on Internet Explorer 6-based web applications, you must create a comprehensive strategy and execution plan to migrate the legacy applications to Internet Explorer 10.
Microsoft recommends that you consider testing or adding a parallel project for Internet Explorer 10 if you’re currently testing, piloting, or deploying Internet Explorer 9. Also, note that Internet Explorer 6 can’t run natively on any later version of Internet Explorer, so the option of running two versions of Internet Explorer simultaneously isn’t supported. For more information, see the Microsoft Knowledge Base article Running Multiple Versions of Internet Explorer on Single Operating System is Unsupported.
Web standards and application compatibility
Before getting into the specifics of design change impacts, it is important to address web standards and their impact on application compatibility. Standards provide a common baseline of technologies, allowing users to select the web browser of their choice and be reasonably confident they will be able to use the websites they want. Standards also allow web designers and developers to create a single implementation of a website, with the expectation that everyone will be able to use it. By increasing choice and reducing fragmentation, everyone wins.
In the world of web browsers, standards are constantly evolving and browsers are continuously being updated to adopt these standards. Consequently, it is very important that IT professionals along with their development teams ensure web applications are compatible with current and emerging web standards and browsers. Doing so ensures the web applications and sites are compatible with new releases of the browser, and helps prevent many compatibility issues that might otherwise arise.
For additional information about planning for application compatibility and migration processes, see Windows 8 Technical Library on TechNet, or see the topics in the Determining Possible Compatibility Issues and Solutions section of the Internet Explorer 10 Deployment Guide.