Systems and methods are provided for cross-platform rendering of video content on a plurality of different user-computing platform types. A script is transmitted to the user-computing platform and is interpreted by an application program to: decode a first type of encoded video data into first decoded video data; render the first decoded video data; determine a rate at which the first type of encoded video data is being received; and, in dependence on the determined rate, to perform at least one of: transmitting a request to receive a second type of encoded video data; modifying a characteristic of the decoding of the first type of encoded video data; and modifying a characteristic of the rendering of the first decoded video data.