Sarama is an MIT-licensed Go client library for Apache Kafka.
You might also want to look at the Frequently Asked Questions.
Sarama provides a "2 releases + 2 months" compatibility guarantee: we support the two latest stable releases of Kafka and Go, and we provide a two month grace period for older releases. However, older releases of Kafka are still likely to work.
Sarama follows semantic versioning and provides API stability via the gopkg.in service. You can import a version with a guaranteed stable API via http://gopkg.in/Shopify/sarama.v1. A changelog is available here.