Could you help us understand what you mean by "online compilers"? If you want to show working examples on a website there is a limited web based editor and execution environment. An example of this is on the main robot framework website under the "Getting Started" section. In general Robot Framework test scripts are executed from a command line or terminal using Python behind the scenes. For more on how to install Robot Framework and Python the Guides can walk one through the installation and initial execution steps. On a more techincal level, Robot Framework could be consider a just in time compilation so other than the previously mention script and Python packages there is not really a compiler per say. If you tell me more about what you are looking for then I might be able to better answer your specific question.