1. A method comprising: receiving a notification indicating that a resource is stored in a resource store; determining a resource category for the resource based, at least in part, on metadata of the resource, in response to said receiving the notification indicating that the resource is stored in the resource store; determining whether a resource index schema for the resource can be identified based on the resource category for the resource; in response to determining that the resource index schema for the resource category can be identified, identifying the resource index schema for the resource, wherein the resource index schema indicates a resource property of the resource; determining, from the metadata of the resource, a property value for the resource property indicated in the resource index schema for the resource category; creating a first index document that has a format independent of a format of the resource, that indicates the resource property and the property value, and that references the resource in the resource store of heterogeneous native format resources; in response to determining that the resource index schema for the resource cannot be identified, identifying a generic schema that indicates at least one property related to storing the resource in a resource store; identifying a property value of the resource for the at least one property indicated in the generic schema; creating a second index document that has a format independent of a format of the resource, that indicates the at least one property identified in the generic schema and the corresponding property value, and that references the resource in the resource store of heterogeneous native format resources; and storing the first index document or the second index document in an index store that comprises a plurality of index documents, wherein the first index document, the second index document, and the plurality of index documents have common formatting.