1. A method performed by a client network node executing a client application integrating web browsing and network data stream processing for realtime communications, the method comprising: on a display, displaying a graphical user interface providing a single point of control for realtime communications and web browsing interactions, wherein the displaying comprises displaying in the graphical user interface at least one control for establishing a presence in a virtual area; requesting a presence in a particular virtual area identified in connection with the control and establishing a realtime communication session with at least one other client network node that is present in the particular virtual area; transmitting outgoing data streams to and receiving incoming data streams from one or more other network nodes over respective network links via the realtime communications and web browsing interactions, the incoming and outgoing data streams comprising one or more time-critical types of data streams and one or more non-time-critical types of data streams, wherein the transmitting and receiving comprise, by the client network node, transmitting and receiving one or more time-critical types of data streams with each at least one other client network node and executing the client application to interface the client network node with network protocols on the client network node; processing the one or more time-critical types of data streams and the one or more nontime-critical types of data streams; monitoring at least one metric characterizing operation of the client network node during the processing of at least one of the time-critical types of the data streams; and in response to a determination that the at least one metric fails to satisfy at least one operational target, dynamically adjusting the operation of the client network node with respect to at least one of the time-critical types of data streams and the non-time-critical types data streams in accordance with a realtime performance targeting process.