Blisk!

Browserstack is a useful online tool which allows users to test their website from different browsers. The list of supported browsers includes Google Chrome, Internet Explorer, Opera, and Safari. This even includes different browser versions as well including the beta versions as well. With Browserstack, you can test every aspect of your website like flash, CSS, Java, and more.

Emmet Re:View displays your responsive web-page in a number of views side-by-side so you can quickly test how web-page looks at different resolutions and devices. All views are fully synchronized: scroll, fill-in form fields, click, hover and drag elements in one view and get instant feedback in all others.

Browsershots makes screenshots of your web design in different browsers. It is a free open-source online service created by Johann C. Rocholl. When you submit your web address, it will be added to the job queue. A number of distributed computers will open your website in their browser. Then they will make screenshots and upload them to the central server here.

The all-in-one web testing platform supports manual, visual, and automated testing across more than 1500 different desktop and mobile browser configurations. Test on Safari, Internet Explorer, Android, iOS, and more.

Browserling lets you quickly cross-browser test your websites in all the most popular browsers, such as Internet Explorer, Chrome, Safari, Opera and Firefox. We run the browsers in virtual machines and you get live access to them.

MultiBrowser (or Multi-Browser Viewer) is a cross browser and functional web testing software tool, using REAL standalone browsers, an accurate mobile emulator and integrates seamlessly with Visual Studio and Selenium for automated testing.

Browshot is a powerful service to take real-time screenshots in 30+ screen resolutions on 15+ virtual devices, including iPhone, Nook, Android, etc. Browshot provides full support for HTML5, CSS3, Flash, JavaScript, etc. You can request thumbnails of any size and any ratio.