These are the *current* maintainers of Dia:

Name: Lars Clausen
Email: lars@raeder.dk

Name: Hans Breuer
Email: hans@breuer.org

These are the previous maintainers of Dia:

Name: Cyrille Chepelov
Email: cyrille@chepelov.org

Name: James Henstridge
Email: james@daa.com.au

Name: Alexander Larsson
Email: alexl@redhat.com