You may be wanted to test your website or the web application you are developing in different operating Systems and different browsers to check how it looks? Browsershots is a website service which can help you on this.
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.
The website also offers different versions of same browser on Linux, Windows and Mac operating systems.
You can see samples below
So you can test your site Here