Open standards have streamlined browser testing by providing a common framework for browsers to follow, but they do not guarantee full browser standardization or compatibility. The implementation of open standards can vary between browsers and operating systems, making it impossible to rely on successful tests in one browser to ensure compatibility with all standards-compliant browsers. Browser vendors have significant motivation to add enhancements of their own, which can lead to non-standard features that may not be compatible with other browsers, even if they are fully compliant with existing open standards. To maintain full browser compatibility, developers need to use triage-based testing strategies, automate and test in parallel, keep it simple, establish a backwards-compatibility policy, avoid single-platform features, and stay alert to changes in browsers and operating systems.