Awesome Java - A curated list of awesome Java frameworks, libraries and software
awesome-java - A curated list of awesome frameworks, libraries and software for the Java programming language.
useful-java-links - A list of useful Java frameworks, libraries, software and hello worlds examples
rest.li - REST+JSON framework for building robust, scalable service architectures using dynamic discovery and simple asynchronous APIs.
lmdbjava - Lightning Memory Database (LMDB) for Java: a low latency, transactional, sorted, embedded, key-value store
JGraphT - mathematical graph-theory objects and algorithms
JUNG - Java Universal Network/Graph Framework
Redisson - Redisson - distributed Java objects and services on top of Redis server
caffeine - A high performance caching library for Java
Algorithms - A collection of algorithms and data structures