A system and a method of playing rich internet applications on remote computing devices by using a certifying player to invoke server-side web services through a single, secure, certifying intermediary server. The application player resides in the remote computing device and is configured to be executed by the remote computing device. The intermediary server is configured to communicate with the remote computing device via a network connection and to receive message requests from the application player and to send message responses to the application player. The intermediary server provides access of the RIA to the remote computing device by accessing an application server, where the RIA resides, via a single, secure and access-controlled network connection. The application player requests functionality of the RIA from the intermediary server via message requests and interprets the message responses received from the intermediary server. The message requests and responses may be Extensible Mark-up Language (XML) messages.