Abstract: Systems, methods, and apparatus (including computer program apparatus) for a browser-aware application delivery system. The System provides World Wide Web browser extensions based on server processes rather than on plug-in program modules loaded and installed on a user's machine. The system operates like a monitor for a user while the user is browsing the web, and enables the user to obtain and interact with context-sensitive services and information based on the user's browsing activity. The system allows the user to add application tools, which are implemented on servers separate from the user's computer. Third parties can easily add tools to the system by registering application services with the system.