Selenium IDE - Selenium IDE is a Firefox add-on that records clicks, typing, and other actions to make a test, which you can play back in the browser.
What Is My Browser - Check your web browsing set up to make sure your software is up to date.
browserling - Live interactive cross-browser testing from your browser.
Support Details - Make tech support easier by examing their browser details
Sidekick Browser - The fastest browser for work ever made
Browse Happy - Presents the user with a list of the most popular modern browsers with links to download the latest version of each.