Visual/UML Schema Design Tools

[Jon Steer <jsteer@bitscout.com>]

Hi,

 I have a fairly complex set of schemas to design and implement so I've 
been looking around
 for some visual design tools for LDAP.

 I've run across the Visio templates (but unfortunately, they don't export).

The standard commercial directory servers appear to have something, but there
aren't any screenshots so it is hard to tell how complete they are.

Are there any open-source/low cost Schema design tools?

 thanks,
jon