Add-on module for Jackson (https://github.com/FasterXML/jackson/) to support Kotlin language, specifically introspection of method/constructor parameter names, without having to add explicit property name annotation.

AnnotationIntrospectors that use Paranamer (http://paranamer.codehaus.org) to introspect names of constructor (and factory method) parameters.

A utility for writing module-info.class files based on YAML and automatic input

Stuff to make integration with Guice a bit easier

Functionality for implementing interfaces and abstract types dynamically ("bean materialization"), integrated with Jackson (although usable externally as well)

A Doxia module for Markdown source documents.

Support for using JAXB annotations as an alternative to "native" Jackson annotations, for configuring data-binding.

jackson-module-scala

PowerMock support module for JUnit 4.x.

A Java-based multi-module build system that infers what to do by inspecting project structure via pluggable extensions, then executes a dependency-ordered graph of tasks — no build scripts required.