Nearly everyone runs Unit tests or functional tests on continuous integration server(s), but how about automated UI testing? There is a number of great test automation tools that can perform visual web UI testing, but integrating them with popular CI solutions would be quite problematic.
The problem is that few UI test automation tools have full support of different CI solutions. If we take Selenium, even this famous tool does not provide an easy universal way to do that. There is a special Selenium plugin designed by Jenkins though. TeamCity, Bamboo and Travis also have their own special solutions for running Selenium tests.
But there is a UI testing tool which provides its own unified solution for integration with major CI tools - Screenster! Thanks to it, Screenster visual tests can be easily used for CSS regression testing with Jenkins, as well as Travis, Bamboo and others. It really helps a lot when you build a big web UI project with rich functionality.