I'm preparing an internal presentation of ZooKeeper and looked again over the
lists of projects using ZooKeeper. However I believe that there may be many
more projects (and companies!) using ZooKeeper.
If you like to be listed, you can either enter your project on the wiki page
yourself (you need to register for a wiki account) or just reply to this
message and I'll post an entry for you.
Best regards and thank you,
Thomas Koch, http://www.koch.ro