1. A method performed on one or more computing devices, wherein the method involves virtual workspaces associated with users of a repository that supports versioning of a plurality of resources, the method comprising the steps of: storing and maintaining, in a shared workspace, a first reference that establishes a relationship between (a) a shared version of a resource and (b) the shared workspace, wherein the resource is one of the plurality of resources; maintaining, for the shared workspace, a hierarchical folder structure that represents actual storage of folders in the repository without maintaining, for any virtual workspace of the plurality of virtual workspaces, a copy of the hierarchical folder structure; wherein the plurality of virtual workspaces includes a first virtual workspace and a second virtual workspace; allowing only a first user, of a plurality of users, access to the first virtual workspace; allowing only a second user, of the plurality of users, access to the second virtual workspace; wherein a first mapping belongs only to the first virtual workspace; wherein a second mapping belongs only to the second virtual workspace; in response to input from the first user, making personal the shared version of the resource; in response to making personal the shared version of the resource, creating and storing, in the first virtual workspace, a second reference that establishes a relationship between (c) the version of the resource that is personal to the first user and (d) the first virtual workspace, while continuing to maintain the first reference that establishes the relationship between the shared version of the resource and the shared workspace; wherein creating and storing the second reference includes creating an entry in the first mapping; wherein the entry includes information that identifies a resource version identifier that corresponds to the version of the resource that is personal to first user; wherein the version of the resource that is personal to the first user is a personal version; wherein the personal version is only accessible to the first user while the personal version is personal to the first user; continuing to maintain, for the shared workspace, the hierarchical folder structure without maintaining, for any virtual workspace of the plurality of virtual workspaces, a copy of the hierarchical folder structure.