Spoon Browser Sandbox is a free, cloud-based service that runs popular browsers directly from the Web without installing them on your PC. It allows you to use almost all web browsers without installing on your machine.
Browsershots allows you to test a website in any browser and operating system. This is a widely used cross browser testing tool because of its features and available customizations. It allows users to preview a website across almost 40 different browsers, provides a full-screen preview for each selected browser and supports optional settings. 
IE NetRenderer is a free online browser compatibility check tool to test a website on almost all versions of Microsoft Internet explorer. It is a free open-source online web application providing developers a convenient way to test their website’s browser compatibility in one place. 
IE Tab is an extension for the mozilla firefox, flock, google chrome and sea monkey web browsers which allow users to view a page using the Internet explorer layout engine. This may be useful for viewing pages that only work in Internet explorer without exiting the user's preferred web browser. Its features include easy browsing, high performance, advanced security, powerful personalization, and cutting edge universal access.
IE Tester is an application that allows testing on multiple IE versions at the same time in the same application. IE Tester, a free cross browser testing tool, can be used to test a website on IE5.5, IE6, IE7, IE8 and IE9, preview browsers on windows 7, vista and XP operating systems. It includes pointer modes, image viewing, DOM highlighting, positioning guides/rulers, layout views, multiple resolutions, thumbnail display etc.
Microsoft Expression Web Super preview free cross browser testing software allows you to test and debug layout issues across different IE browsers and platforms. It speeds the essential task of browser compatibility testing. With Super preview, one can debug your pages on the same machine that we use for development. It supports both windows and macintosh browsers, runs locally and as a web service, compares pages side by side or overlaid, element & DOM tree information speeds debugging etc.
Browsera is an all-in-one, web-based tool for testing web sites for errors, complications, and layout issues. Unlike other similar tools, it does more than just take screen shots of various browsers; it provides an in-depth assessment of problematic areas in need of attention. It automatically highlights browser layout problems, locates java script errors, easily tests entire sites, tests dynamic pages and does not require any installation.
Adobe BrowserLab is an online service that helps ensure your web content displays as intended. It accurately previews web pages across multiple browsers and operating systems, navigates links, and uses diagnostic tools to optimize websites efficiently. It supports extensive previews, allows viewing of previews in multiple ways, tests content easily and integrates with your work flows, customizes your test settings and allows integration with dream weaver. 
BrowserCam is a paid online service that allows you to view your web pages across different platforms and browsers, either by automatically taking the screen shots of your choice or by accessing computers remotely. Its features are unlimited usage, priority capture queue, double remote access session time, device captures included for your mobile page development needs, waterfall object analysis included etc. 
BrowserSeal is a fast and easy to use cross browser testing and screen shot tool. It allows you to capture an image of your web site under multiple browsers with a single click of a mouse and instantly inspect the differences. Its provides standalone versions of all browsers, allows testing local and intranet websites, command line interface for automation scripting, opera mini 5.1 for cellular browser testing etc. It is the fastest and the most user friendly, cross browser testing tool available today.
Cloud Testing service allows you to automate the functional and cross browser testing of your websites using the industry standard selenium framework and real browsers real operating systems. It supports testing of website using real browsers, supports screen shots comparison, finds defects faster, provides full debug and diagnostics capability, automates your testing etc. It offers a suite of services that allow developers, testers and website managers to automate and speed up the testing of their websites using real browsers from the cloud.
CrossBrowserTesting.com provides the ability to test a website across majority web browsers. It is a dead simple implementation with an easy-to-use graphical interface and an HTML/JS editor for experts. It allows full testing of a site’s interactivity.
