I used this at my last job, it is open source and HIGHLY customizable. I taylored it to my specific needs, if you are good with PHP/MySQL then you could get it to work for your needs.
http://sourceforge.net/project/showfiles.php?group_id=58053 And if you are worried about security, DCE/DFS integrated well with it (could substitute krb5 or simply ssl) I talked to my old employer recently and they are still happily using it (and begging for more customizations/functionality) Steve -- TriLUG mailing list : http://www.trilug.org/mailman/listinfo/trilug TriLUG Organizational FAQ : http://trilug.org/faq/ TriLUG Member Services FAQ : http://members.trilug.org/services_faq/ TriLUG PGP Keyring : http://trilug.org/~chrish/trilug.asc
