Extending operating system subsystems

A method performed by a computer system for extending a subsystem of an operating system, the subsystem of the operating system having a set of insertion points, the insertion points identifying points in the program logic of the subsystem of the operating system where logic extensions may be added, the method comprising:

• receiving a library having functions and a list, the functions comprising program logic for extending the subsystem of the operating system and corresponding to at least a subset of the set of insertion points, the list providing a correspondence between the insertion points and the functions;
• receiving a request to perform an action, the action generally associated with the subsystem of the operating system;
• determining from the list whether a function appears in the library that corresponds to the requested action;
• and
• when a function appears in the library that corresponds to the requested action, performing the function.

A computer-readable medium having computer-executable instructions for extending a subsystem of an operating system, the subsystem of the operating system having a set of insertion points, the insertion points identifying points in the program logic of the subsystem of the operating system where logic extensions may be added, the method comprising:

• receiving a library having functions and a list, the functions comprising program logic for extending the subsystem of the operating system and corresponding to at least a subset of the set of insertion points, the list providing a correspondence between the insertion points and the functions;
• receiving a request to perform an action, the action generally associated with subsystem of the operating system;
• determining from the list whether a function appears in the library that corresponds to the requested action;
• and
• when a function appears in the library that corresponds to the requested action, performing the function.