9. A non-transitory computer-readable medium having stored contents that configure a computing device to perform a method, the method comprising: an itemMirror library providing support, in software applications that use the library, for: a. storing metadata in association with any grouping item; b. retrieving metadata previously stored in association with any grouping item; c. storing metadata in association with any reference in any grouping item to another information item; d. retrieving metadata previously stored in association with any reference in any grouping item to another information item; e. using drivers to store and retrieve information via an application programming interface (API) as supported by a separate application, database or cloud store service; f. controlling concurrency of access to ensure that the modifications in metadata made by one software application are sequenced to occur strictly before or after the modifications made by another software application.
9. A non-transitory computer-readable medium having stored contents that configure a computing device to perform a method, the method comprising: an itemMirror library providing support, in software applications that use the library, for: a. storing metadata in association with any grouping item; b. retrieving metadata previously stored in association with any grouping item; c. storing metadata in association with any reference in any grouping item to another information item; d. retrieving metadata previously stored in association with any reference in any grouping item to another information item; e. using drivers to store and retrieve information via an application programming interface (API) as supported by a separate application, database or cloud store service; f. controlling concurrency of access to ensure that the modifications in metadata made by one software application are sequenced to occur strictly before or after the modifications made by another software application. 13. The computer-implemented method of claim 9 wherein some of the metadata stored, and later retrieved, is generic and applies no matter which tool or application is using the data.