Javaslang is an object-functional language extension to Java 8, which aims to reduce the lines of code and increase code quality. It provides persistent collections, functional abstractions for error handling, concurrent programming, pattern matching and much more. Javaslang fuses the power of object-oriented programming with the elegance and robustness of functional programming. The most interesting part is a feature-rich, persistent collection library that smoothly integrates with Java's standard collections.