A community driven list of useful Scala libraries, frameworks and software. This is not a catalog of all the libraries, just a starting point for your explorations. Inspired by awesome-python. Other amazingly awesome lists can be found in the awesome-awesomeness list.

• Awesome Scala
  • Database
  • Web Frameworks
  • i18n
  • Authentication
  • Testing
  • JSON Manipulation
  • Serialization
  • Science and Data Analysis
  • Big Data
  • Functional Reactive Programming
  • Modularization and Dependency Injection
  • Extensions
  • Android
  • HTTP
• Contributing

Database access libraries in Scala.

• ScalikeJDBC — A tidy SQL-based DB access library for Scala developers.
• Slick — Modern database query and access library for Scala.
• Squeryl — A Scala DSL for talking with databases with minimum verbosity and maximum type safety.
• Activate — Pluggable object persistence in Scala.
• Scala ActiveRecord — ORM library for scala, inspired by ActiveRecord of Ruby on Rails.
• PostgreSQL and MySQL async — Async database drivers to talk to PostgreSQL and MySQL in Scala.
• ReactiveMongo — Reactive Scala Driver for MongoDB.
• Phantom — Async type safe Scala DSL for Apache Cassandra.
• ReactiveCouchbase — Reactive Scala Driver for Couchbase. Also includes a Play plug-in. An official plug-in is also in development.

Scala frameworks for web development.

• Play — Makes it easy to build scalable, fast and real-time web applications with Java & Scala.
• Skinny Framework — A full-stack web app framework upon Scalatra for rapid Development in Scala.
• Scalatra — Tiny Scala high-performance, async web framework, inspired by Sinatra.
• Spray — A suite of scala libraries for building and consuming RESTful web services on top of Akka.
• Finatra — A sinatra-inspired web framework for scala, running on top of Finagle.
• Reactive — FRP and web abstractions, which can be plugged into any web framework (currently only has bindings for Lift).
• Chaos — A lightweight framework for writing REST services in Scala.
• Xitrum — An async and clustered Scala web framework and HTTP(S) server fusion on top of Netty, Akka, and Hazelcast.
• Unfiltered — An modular set of unopinionated primitives for servicing HTTP and WebSocket requests in Scala.

Scala libraries for i18n.

• Scaposer – GNU Gettext .po file loader for Scala.
• scala-xgettext – A compiler plugin that acts like GNU xgettext command to extract i18n strings in Scala source code files to Gettext .po file.

Libraries for implementing authentications schemes.

• scala-oauth2-provider — OAuth 2.0 server-side implementation written in Scala.
• SecureSocial — A module that provides OAuth, OAuth2 and OpenID authentication for Play Framework applications.
• play2-auth — Play2.x Authentication and Authorization module.
• play-pac4j — Profile & Authentication Client in Scala (and Java) for CAS, OAuth, OpenID, SAML, HTTP... protocols and Play 2.x framework.

Libraries for code testing.

• ScalaCheck — Property-based testing for Scala.
• ScalaTest — A testing tool for Scala and Java developers.
• Specs2 — Software Specifications for Scala.
• µTest — A tiny, portable testing library for Scala.
• Scalive — Connect a Scala REPL to running JVM processes without any prior setup; this library is used for inspecting systems in production mode.

Libraries for work with json.

• json4s — Project aims to provide a single AST to be used by other scala json libraries.
• spray-json — Lightweight, clean and efficient JSON implementation in Scala.
• argonaut — Purely Functional JSON in Scala.
• jackson-module-scala — Add-on module for Jackson to support Scala-specific datatypes.
• play-json — Flexible and powerful JSON manipulation, validation and serialization, with no reflection at runtime (docs, published separately at "com.typesafe.play" %% "play-json" % playVersion).

Libraries for serializing and deserializing data for storage or transport.

• Pickling — Fast, customizable, boilerplate-free pickling support.
• scodec — A combinator library for working with binary data.
• Scrooge — An Apache Thrift code generator for Scala.
• validation — Advanced validation & serialization for JSON, HTML form data, etc, with no reflection at runtime (intro).

Libraries for scientific computing, data analysis and numerical processing.

• Breeze — Breeze is a numerical processing library for Scala.
• MLLib — Machine Learning framework for Spark
• Spire — Powerful new number types and numeric abstractions for Scala.
• Algebird — Abstract Algebra for Scala.
• FACTORIE — A toolkit for deployable probabilistic modeling, implemented as a software library in Scala.
• Saddle — A minimalist port of Pandas to Scala
• Squants — The Scala API for Quantities, Units of Measure and Dimensional Analysis.
• MGO — Modular multi-objective evolutionary algorithm optimization library enforcing immutability.

• Spark — Lightning fast cluster computing — up to 100x faster than Hadoop for iterative algorithms (memory caching) and up to 10x faster than Hadoop for single-pass MapReduce jobs. Compatible with YARN-enabled Hadoop clusters, can run on Mesos and in stand-alone mode as well.
• Scalding — A Scala binding for the Cascading abstraction of Hadoop MapReduce.
• Summingbird — An implementation of the “lambda architecture” as a software abstraction — a single API for Hadoop and Storm.
• Scrunch — A Scala wrapper for Apache Crunch which provides a framework for writing, testing, and running MapReduce pipelines.
• GridScale — A Scala API for computing clusters and grids.
• scoozie — Scala DSL on top of Oozie XML.

Event streams, signals, observables, etc.

• Scala.Rx — An experimental library for Functional Reactive Programming in Scala (reactive variables). Scala.js compatible.
• scala.frp — Functional Reactive Programming for Scala (event streams).
• RxJava-Scala — Scala Adaptor for RxJava.

Modularization of applications, dependency injection, etc.

• Domino — Write elegant OSGi bundle activators in Scala.
• Sclasner - Scala classpath scanner.
• Scaldi — Lightweight Scala Dependency Injection Library.
• MacWire — Scala Macro to generate wiring code for class instantiation. DI container replacement.
• SubCut — Scala Uniquely Bound Classes Under Traits.

Scala extensions.

• Scalaz — An extension to the core Scala library for functional programming.
• Shapeless — A type class and dependent type based generic programming library for Scala.
• Twitter Util — General-purpose Scala libraries, including a future implementation and other concurrency tools.
• Scala Async — An asynchronous programming facility for Scala.
• Resolvable — A library to optimize fetching immutable data structures from several endpoints in several formats.

Scala libraries and wrappers for Android development.

• Scaloid — Less painful Android development with Scala.
• Macroid — A modular functional UI language for Android.
• Android SDK Plugin for SBT — An sbt plugin that adds tasks for developing Android applications.

Scala libraries and wrappers for HTTP clients.

• Dispatch — Library for asynchronous HTTP interaction. It provides a Scala vocabulary for Java’s async-http-client.
• Netcaty - Simple net test client/server for Netty and Scala lovers.
• Scalaxb — An XML data-binding tool for Scala that supports W3C XML Schema (xsd) and Web Services Description Language (wsdl) as the input file.
• Spray — Actor-based library for http interaction.
• Tubesocks — Library supporting bi-directional communication with websocket servers.

Your contributions are always welcome! Please submit a pull request or create an issue to add a new framework, library or software to the list. Do not submit a project that hasn’t been updated in the past 6 months or is not awesome.