Rather than hold back the evolution of this site by trying to support legacy browsers, from time to time we take a step forward that may require users to upgrade.
Testing during development, and by the community here, guarantees support for most browsers, but if you are using an antiquated browser, please consider upgrading if possible to avoid potential problems later.
If you are using IE 5.n or above, or Firefox on any platform, then you should experience no problems. If you are an Opera user, please upgrade for free at http://www.opera.com/. IE users on Mac should switch to Safari or Firefox right away. IE on Mac is no longer supported by Microsoft or this site.
If you are at all concerned about support for your browser, please post in this thread with OS and exact browser version details.