Now and then websites are really important for daily business and private life. You can nearly buy everything on websites, find information, meet friends, watch movies and much more. All the worse if your website is not working and you don't notice it or your customer first. But even if you already have some monitoring for webservices or domain name availability, you can't be sure, if your website itself works correct. Maybe the login/logout procedure is broken, some parts of the website are missing or wrong data are presented... You should be prevented for these situations.
Selenium is an automation for browsers and widely used for testing purposes. OpenNMS allows you to run complex web tests with Selenium to ensure web service availabilty and measures response times in the polling framework.
Would you like to know more? -> Selenium Monitor