Acceptance test driven development (ATDD) is an important agile practice merging requirement gathering with acceptance testing. In its core are concrete examples, created together with the team, that provide collaborative understanding and, as automated acceptance tests, make sure that the features are implemented correctly. There are many ways to create ATDD examples/tests, and the behavior driven development (BDD) style with Given-When-Then format is one of the more popular ones. Robot Framework is an open source test automation framework suitable for ATDD and acceptance testing in general. It has a flexible test data syntax that supports keyword-driven, data-driven, and BDD styles, but is still simple enough so that also non-programmers can create and understand test cases. The simple test library API makes extending the framework easy, and there are several ready made libraries that allow testing generic interfaces such as web, databases, Swing, SWT, Windows GUIs, Flex, and SSH out-of-the-box. This presentation gives an introduction both to ATDD and Robot Framework. It contains different demonstrations and all the material will be freely available after the presentation.