Apache Kafka Clients
Clients - Apache Kafka - Apache Software Foundation
https://cwiki.apache.org/confluence/display/KAFKA/Clients
Alternative Java
Of course the main project maintains a set of jvm-based clients. But here are alternate clients.
Krackle is an optimized Kafka client built by Blackberry.
Kafka Version: 0.8.x
Maintainer: Blackberry
License: Apache 2.0
https://github.com/blackberry/Krackle/blob/dev/LICENSE
Scala DSL
A DSL for Scala developers to produce and consume messages with Kafka.
Kafka Version: 0.8.x
Maintainer: Big Data Open Source Security LLC
License: Apache 2.0