Take a look at Nuxeo (www.nuxeo.org). Their ECM application uses Jackrabbit and has work flow management built on top.

.Steve

Torgeir Veimo wrote:
On Tue, 2007-08-07 at 13:12 +0200, Stefan Guggisberg wrote:
  
no. workflow engines and e.g. CMS's are applications
usually built on top of a repository/database.
jackrabbit is a generic content repository and doesn't
come with any applications (much like relational databases
which in general don't support workflows). 
    

It would be interesting to see an example of node type definitions used
to support workflow though.