A library intended to provide abstractions for functional programming in Scala, leveraging its unique features. Design goals are approachability, modularity, documentation and efficiency.
Shapeless is a generic programming library. Starting with implementations of Scrap your boilerplate and higher rank polymorphism in Scala, it quickly grew to provide advanced abstract tools like heterogenous lists and automatic instance derivation for type classes.
Spire is a numeric library for Scala which is intended to be generic, fast, and precise. Using features such as specialization, macros, type classes, and implicits, Spire works hard to defy conventional wisdom around performance and precision trade-offs.
Originally intended for internal use in spire, this library helps libraries declaring type classes to precisely state the laws which instances need to satisfy, and takes care of not checking derived laws multiple times.
A pure functional JDBC layer for Scala. It is not an ORM, nor is it a relational algebra; it just provides a principled way to construct programs (and higher-level libraries) that use JDBC.
Extensible effects are an alternative to monad transformers for computing with effects in a functional way. This library is based on the “free-er” monad and an “open union” of effects described by Oleg Kiselyov in “Freer monads, more extensible effects”
High-performance library for composing asynchronous, event-based programs, exposing a Reactive Streams implementation along with primitives for dealing with concurrency and side-effects.
Strongly inspired by Haskell's lens library, Monocle is an Optics library where Optics gather the concepts of Lens, Traversal, Optional, Prism and Iso.
Tools for refining types with type-level predicates which constrain the set of values described by the refined type, for example restricting to positive or negative numbers.
scodec is a combinator library for working with binary data. It focuses on contract-first and pure functional encoding and decoding of binary data and provides integration into scalaz and shapeless.
A very simple documentation tool for Scala that reads Markdown files and interprets Scala code in tut sheds, allowing you to write documentation that is typechecked and run as part of your build.