A method and apparatus are provided for communicating information and carrying out other interactions between a browser and an application program. A hyperaction protocol is defined that enables a browser to directly call functions of an application program executed by a separate server over a public network. In one embodiment, in the course of parsing and displaying an HTML document or other HTML source text, a browser encounters or receives a hyperaction request of the form "hyperaction://#." In response, the browser identifies a function or other action of a separate application. The browser calls that function of the application over the network and provides the payload. When a response is received, the browser extracts data values or function results provided by the application. As a result, a browser can directly interact with an application without using scripts or other awkward mechanisms of existing protocols.