Described herein are one or more computer operating environments that include a standard set of web services via a communications network (e.g., the Internet) and a mechanism for extending the standard set of web services to execute one or more extended web services. Since these extended web services may be produced by an unconfirmed or untrusted source (e.g., a third-party software developer), the described computer operating environments isolate the extended web services from the standard set of web services and from the communication network. Furthermore, each extended web service is an isolated process (isoproc) with a limited ability to communicate with other services. In particular, each isoproc's ability to communicate is limited to only associated defined communication channels over which it has express permission to communicate.