Publish-subscribe systems and Erlang - a perfect fit. Oortle is an implementation of publish-subscribe messaging system, able to scale (near)linearly in terms of number of clients. Oortle runs in the clouds (EC2 and others). Tests with 200 EC2 node clusters has been done. Single Oortle node can handle hundreds of thousands connections. Practical experience of designing, implementing and testing of the system will be shared with audience.