DAppHack (http://www.dapphack.org/) is a weekend long unconference & hackathon for everyone who cares about systems & protocols without centralised ownership.
Demos & workshops about tools & libraries to use in your DApp directly from those who built:
• Parity (Ethereum Rust implementation)
• Eris by Monax
& something special for Java people - Java library to interact with smart contracts from JVM & more.
Sign up on Eventbrite (https://www.eventbrite.de/e/dapphack-registration-29070767448?aff=eac2).