gradle-sablecc-plugin is a gradle plugin which creates parsers using SableCC. SableCC supports automatic CST-to-AST transformation, emits all the visitor patterns and analysis helpers you will likely ever need, and is LR, not LL(k). Many example grammars are available for modern languages; the author of this plugin has written dozens.
jdiagnostics is a library of routines for inspecting the state of a JVM and building a support bundle. It makes it easy to diagnose issues with classpaths, resources, serviceloaders, versioning, XML parsers, and so forth. It has no dependencies, and is an essential library to build into any infrastructure application.
PRUN is a cluster job scheduler and parallel task executor system for Linux/Unix systems. Like other full-featured batch systems, it provides a job queueing mechanism, job scheduling, a priority scheme, resource monitoring, and resource management. PRUN is a simple, easy-to-use, full-featured, stable solution to run short-term or long-term jobs across the cluster.
Immutables allows you to embrace immutablity to tackle complexity and concurrency challenges. To get the benefits of immutability in Java, there's an annotation processor to easily create simple and consistent value objects. You can think of it as Guava's Immutable Collections but for regular objects. It includes support for JSON marshaling, MongoDB repositories, and JAX-RS.
io-util is a small, scalable Java library for slicing and dicing fixed width tables on disk. The objective is to provide reusable blocks of code for building efficient, custom binary data stores. It allows you to build, search, and maintain a large, externally stored, fixed width, sorted table. The library user specifies the row width (in bytes), a row comparison function (which implicitly defines any given row's key), and an optional delete codec.