The document discusses flexible resources in Eclipse 4.0 and 3.6. It describes how work being done in Eclipse 4.0 on resources can be merged into the 3.x code stream. It provides examples of new resource functionality that originated in Eclipse 4.0 but has been backported to 3.6, such as resource filters and virtual folders. It also outlines plans for a semantic file system in Eclipse to provide more flexible mapping between workspace paths and network locations.