I am the Tigase Server project maintainer.
I have found Tigase source code files taken from the project and copied to the Zimbra source repository. Also the license and authorship information has been changed.
While the Tigase is an open source project and I have no objections with using my code in other project I must insist to preserve the GPLv3 license and original authorship information.
At least 2 files have been directly copied and are identical (except Javadoc) with files from the Tigase source code repository approx 2 years ago:
TLSWrapper and TLSStatus.
I haven't done extensive research to check how much code is used but I am sure someone from Zimbra team can do this.
Please contact me to resolve this.
with best regards,