Systems and methods for deploying rich internet applications in a secure computing environment. An example computer system comprises: a hardware processor and a run-time environment executing a first rich internet application in a first application container and a second rich internet application in a second application container. The run-time environment is configured to: determine, by querying an administration server, whether at least one of the first rich internet application or the second rich internet application is allowed to be executed within the run-time environment, determine whether at least one of the first rich internet application or the second rich internet application is allowed to access a certain function exposed by an application-programming interface (API) of the run-time environment, implement a client-side messaging bus to facilitate communications between the first rich internet application and the second rich internet application, and prevent at least one of the first rich internet application or the second rich internet application from terminating the run-time environment.