Interactive legacy applications can be run from a network, such as the Internet, without requiring any code changes in the application. Typically, legacy applications are critical to a business, are self-contained on the computer, have mixed business and user interface logic, and were written before distributed computing emerged. Separating business logic from user interface logic as required by web application architectures is not practicable in the case of legacy applications. A client has a network user agent which can access a network server connected to the computer. When an application is invoked from the network user agent, a runtime data redirector intercepts the application's raw data and sends the data to the network server which then serves the data across the network to the network user agent. Input data from the user entered through the network user agent are sent back to the application via the same runtime intercept.