9. A non-transitory computer-readable medium containing a program, which, when executed by a processor, performs an operation to generate a document revision history for versions of a document managed by a first electronic document management system (EDMS), the operation comprising, by a second EDMS: importing, from the first EDMS into a first location of the second EDMS, metadata describing a first document revision history for the versions of the document managed by the first EDMS, wherein the first document revision history comprises metadata attributes in a first format associated with the first EDMS and describes an actual revision history of the document; generating, from the metadata describing the first document revision history, a second document revision history comprising metadata attributes in a second format associated with the second EDMS, wherein the second document revision history provides a mirrored revision history mirroring the actual revision history, and wherein one or more metadata attributes in the second format are distinct from one or more corresponding metadata attributes in the first format; importing the second document revision history from the first location into a repository managed by the second EDMS; and importing the versions of the document from the first location into the repository managed by the second EDMS.
9. A non-transitory computer-readable medium containing a program, which, when executed by a processor, performs an operation to generate a document revision history for versions of a document managed by a first electronic document management system (EDMS), the operation comprising, by a second EDMS: importing, from the first EDMS into a first location of the second EDMS, metadata describing a first document revision history for the versions of the document managed by the first EDMS, wherein the first document revision history comprises metadata attributes in a first format associated with the first EDMS and describes an actual revision history of the document; generating, from the metadata describing the first document revision history, a second document revision history comprising metadata attributes in a second format associated with the second EDMS, wherein the second document revision history provides a mirrored revision history mirroring the actual revision history, and wherein one or more metadata attributes in the second format are distinct from one or more corresponding metadata attributes in the first format; importing the second document revision history from the first location into a repository managed by the second EDMS; and importing the versions of the document from the first location into the repository managed by the second EDMS. 11. The non-transitory computer-readable medium of claim 9 , wherein importing the versions of the document comprises storing a unique identifier that identifies each version of the document in the first EDMS.