Hyperledger Hackfests are regular gatherings for developers working on the different projects hosted at Hyperledger.
The primary goal for a Hackfest is to facilitate software development collaboration and knowledge sharing between participants, with an eye towards reflecting all ideas and conclusions back outward to the public open source community afterward. A secondary goal is to bring new contributors and passive observers up the learning curve on the different technology platforms, and the cross-cutting issues affecting multiple projects (such as identity, security, development process, etc). Often the most useful outcome, however, is the strengthened personal relationships between the participants.
Hackfests are public meetings, anyone is welcome to attend and participate no matter what their skill level, though the discussions will presume a significant familiarity with blockchain technologies and software development concepts.
Hackfests are unconferences. This means that the attendees drive the agenda and what topics are talked about. Anyone can propose a topic.