Abstract: Generating a software update catalog may involve accessing resource identifiers. Each resource identifier may identify a location of a portion of update metadata corresponding to a respective program, where the portions of update metadata include information for determining whether to apply their respective updates. The resource identifiers may be used to import the portions of update metadata, and the software update catalog can be generated based on the imported portions of update metadata. Furthermore, a user interface (UI) may be displayed for authoring an update. The UI may allow a user to define the update and signature information by which a computer can be scanned to determine whether the update has been installed and/or whether the update is applicable. An update by generating a portion of update metadata that includes the information that identifies the update and that includes the scan information.