The disclosure provides an approach for installing and deploying a plug-in on a computer system so as to extend an extensible software. The plug-in is encapsulated in an installation file recognizable by the extensible software as indicating that the software modules within the installation file should be installed within their own local scope on the extensible software. The approach further provides a method for handling a request for an application programming interface by a service module of an installed plug-in. The method of handling the request includes determining whether the requested API is within a local scope of the service module, and if so, providing the API from the local scope, or otherwise, providing the API from the global scope of the extensible software.