Workspace 0.4E was released by Michel Belanger and available at http://pages.infinit.net/micbel.
There are lots of changes over the old 0.4D. You can find the changelog at http://pages.infinit.net/micbel/html/0_4D_to_0_4E.htm.
The development version 0.5A (compiled for 6.2NC) is also available.