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 high-throughput computing software framework for coarse-grained distributed parallelization of computationally intensive tasks. It provides a job queueing mechanism, job scheduling, a priority scheme, resource monitoring, and resource management. PRUN is a lightweight, 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.