RxJava – Reactive Extensions for the JVM – a library for composing asynchronous and event-based programs using observable sequences for the Java VM.

OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec (v2, v3)

Reactive Streams Specification for the JVM

Generates TypeScript from Java - JSON declarations, REST service client

A Java library for parsing and building iCalendar data models

A collection of algorithms for mining data streams

Start GraalVM with access to NodeJS modules from Java/Kotlin

HTML5 SnapChat clone developed with Spring and AngularDart

A library for working with Bitcoin

Java library for the new cryptographically secure BitPay API