I did for our distribution. ROSA Linux. ROSA It's for Zimbra 7.2.0.
- binary.sh. It compresses some binary files.
- scripts.tar.bz2. It merges zimbra*.spec files to zimbra.spec
1) Replacement. Heimdal kerberos -> MIT Kerberos. ThirdParty.
2) An external OpenLDAP. Automatic updating. Dynamic and static configuration. New scripts. A wrapper for LDAP requets. Relocating root DN.
3) rpm packages. Automatic updating. It can restart only needed components. I changed zmcontrol.
4) Working SPNEGO. Linux. I changed admin.jdp and login.jsp and other files.
5) Setup changes for Kerberos. I changed zmsetup.pl and other files.
6) .../ThirdPartyBuilds/build/opt/zimbra/... I changed the building system. Not only root. Any user can build it.
7) Web UI. Address book. I added a button. It shows all users in the global address list. It's very comforting to see them all without searching.
8) Clean operation. It can malformed during configuring. You can reset it.
9) I removed versions for automatic updating. /opt/zimbra/mysql/ , /opti/zimbra/jetty and etc.