Since the last release, some highlights-

• Test suites
• The open attribute and other state calls use the same backing value
  • open is observed by the browser
• Better support for <form method="dialog"> and setting returnValue
• More stable class-based rewrite
• Limit to number of open modal dialogs
• Simplified focus blocking
• Other minor updates to match the W3C spec
  • Default CSS updates for small-screen browsers

Additionally, note that dialogPolyfill.registerDialog is now a noop on browsers with dialog support, such as Chrome. If you'd like to force use of the polyfill (with unpredictable results), please call dialogPolyfill.forceRegisterDialog.

There are still some unresolved issues in IE9/10. We'd appreciate user feedback.