A configuration as code language with rich validation and tooling.
Manifold is a Java compiler plugin, its features include Metaprogramming, Properties, Extension Methods, Operator Overloading, Templates, a Preprocessor, and more.
Maven plugin which includes build-time git repository information into an POJO / *.properties). Make your apps tell you which version exactly they were built from! Priceless in large distributed deployments... :-)
Get rid of the boilerplate code in properties based configuration.
Let Fixture Monkey generates fully-customizable, randomly populated instance. Focus on the properties of the class that really matter in your test.
OAuth2 / OIDC for Spring backends of SPAs and mobile apps: the Spring Security beans the official starters leave to you (authorities, CORS, 2xx/401 for fetch, CSRF cookie, validated redirects, logout, one refresh flow at a time), as properties.
QuickPerf is a testing library for Java to quickly evaluate and improve some performance-related properties