1. A computer-readable medium embodying computer-executable code that implements a software architecture, the architecture comprising: multiple attachment points collectively arranged to filter data associated with files that describe software extensions, each attachment point including logic for filtering data; and multiple extension managers associated with the multiple attachment points and with respective feature types that can be added to a software platform by software extensions, the extension managers being configured to receive data from the multiple attachment points that pertains to the feature type with which the extension manager is associated.