1. A computer-implemented method of generating a document revision history for versions of a document managed by a first electronic document management system (EDMS), the method 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.
6. The method of claim 1 , further comprising: prior to generating the second document revision history, determining that one or more of the versions of the document are stored in the second EDMS and determining that the document has been modified by users of the first EDMS and second EDMS after previously being imported; and when importing the second document revision history from the first location into the repository managed by the second EDMS, overwriting at least a portion of the second document revision history with an existing revision history associated with the one or more versions of the document stored in the second EDMS.