Internet Explorer (IE) the most used browser worldwide, and due to this, Microsoft puts in a lot of effort to develop new features for this application. One of the inconveniences that arise when a new version is launched is that, by default, when installed it overwrites the old version of the product. To avoid this problem, and to allow their users to try the new browser without uninstalling Internet Explorer 6, Microsoft developed Internet Explorer 7 Standalone.
Version 7 of Microsoft's browser
Internet Explorer 7 Standalone is a small program that allows users to install IE7 on their computer and try out all the new features that it includes (tab-based browsing, IDN help with antiphishing protection, CSS improvements, etc.) without having to overwrite there old copy of the browser, something that was also very convenient for web developers because they had to test how their websites worked on several versions of the same browser.
All in all, if you want to try out Internet Explorer 7 without affecting older installations of the browser that are already installed on the computer, download and try out Internet Explorer 7 Standalone.