tab Zimlets in ZCS 8.0

Hi,
I am testing ZCS 8 Open Source edition.
I am looking to develop zimlets, and have been unable to find documentation for 8, so followed the
developers guide to 6/7 here ZCS 6.0:Zimlet Developers Guide:Introduction - Zimbra :: Wiki
and was able to create the "Hello World" zimlet without any problems.
I went on to the simple tab zimlet, and it does not work, no tab shows up.
I also tried an simple tab example I found here, but no luck.

Do tab zimlets work with 8.0, is there any guides out there, I wouldn't even know where to start.

Thanks.