Good question, according to the PoweredBy wiki not too much ;-)
(please update this if your company is using...)
So far we have 5 committers (Ben, Andrew, Flavio, Mahadev and myself)
and just a few contributors.
There are a number of teams using ZK inside Yahoo, Veoh is using ZK (Ted
Dunning gave a talk with Ben at the last Hadoop social), spinn3r, and it
looks like IONA might have some interest. :-)
A number of people attending the last Hadoop social indicated that they
are using or looking at ZK.
Hiram Chirino wrote:
How big is the ZooKeeper developer community and what commercial
associations do they have?