Browse free open source Scala Libraries and projects below. Use the toggles on the left to filter open source Scala Libraries by OS, license, language, programming language, and project status.

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  • 1
    Lagom

    Lagom

    Reactive Microservices for the JVM

    The opinionated microservices framework for moving away from the monolith. Lagom helps you decompose your legacy monolith and build, test, and deploy entire systems of Reactive microservices. Lagom is an open source framework for building systems of Reactive microservices in Java or Scala. Lagom builds on Akka and Play, proven technologies that are in production in some of the most demanding applications today. Lagom's integrated development environment allows you to focus on solving business problems instead of wiring services together. A single command builds the project, starts supporting components and your microservices, as well as the Lagom infrastructure. The build hot-reloads when it detects changes to source code.
    Downloads: 0 This Week
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  • 2
    Maoz is a scala port of ... (you guess:-)
    Downloads: 0 This Week
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  • 3
    Monocle

    Monocle

    Optics library for Scala

    Monocle is a pure functional, optics library for Scala providing immutable data access and transformation tools — including Lens, Prism, Iso, Optional, and Traversal. It enables composable, declarative modifications of deeply nested immutable structures in a concise and type-safe fashion.
    Downloads: 0 This Week
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  • 4
    RedRoo implements a framework for defining and executing hierarchical state machines. As a Red Kangaroo jumps from place to place, RedRoo will transition your application from state to state feeding on the events you pass to it. So get jumping!
    Downloads: 0 This Week
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  • 5
    Refined

    Refined

    Refinement types for Scala

    Refined is a Scala library that enhances types with compile-time constraints using predicate-style refinement types. It allows embedding validation logic into types like Refined[Int, Positive], ensuring invalid values are rejected at compile or runtime, thereby increasing safety and reducing boilerplate in domain modeling.
    Downloads: 0 This Week
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  • 6
    Regular Expression Builder for Java (reb4j) is a simple set of classes that encapsulate the regular expressions used by java.util.regex.Pattern and provide facilities for composing larger expressions from sub-expressions.
    Downloads: 0 This Week
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  • 7
    Math expression parser and evaluator written in Scala. Usable from Java (Sun JRE 1.6) Provides float, integral, boolean and vector data types, some string processing support. Variables may be defined internally or im- and exported through a binding.
    Downloads: 0 This Week
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  • 8
    Library allowing scala classes to easily implement state charts. The library handles asynchronous consumption of events and traversal through state charts.
    Downloads: 0 This Week
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  • 9
    Scalaffinity
    Scalaffinity is a library providing a core of functionalities for any social networking web site extracting and leveraging collective intelligence. Scalaffinity is built using Scala, Spring, JPA+Hibernate(Search)+EHCache, JUnit+DBUnit, Maven...
    Downloads: 0 This Week
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  • 10
    Scalargs is a Scala library for parsing command line options as easily as possible.
    Downloads: 0 This Week
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  • 11
    Scalaz

    Scalaz

    Principled Functional Programming in Scala

    Scalaz is a foundational functional-programming library for Scala that provides type classes, data types, and syntax to write pure, composable code. It implements classic abstractions such as Functor, Applicative, Monad, Monoid, Foldable, and Traverse, along with powerful transformers (ReaderT, StateT, WriterT, OptionT, and more) to structure effects. The library offers rich data structures—\/ (disjunction), Validation, NonEmptyList, IList, and Free—that help model errors, invariants, and interpretable programs. Its type class–oriented design lets you write generic algorithms over capabilities rather than concrete types, improving reuse and testability. Scalaz also contributes optics, equality/ordering abstractions, and lawful instances with property-based tests to ensure algebraic laws hold. While the Scala ecosystem now includes sibling projects, Scalaz remains a deep toolbox for principled FP in Scala and a reference point for category-theory-inspired design on the JVM.
    Downloads: 0 This Week
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  • 12
    ScalikeJDBC

    ScalikeJDBC

    A tidy SQL-based DB access library for Scala developers

    ScalikeJDBC is a tidy SQL-based DB access library for Scala developers. This library naturally wraps JDBC APIs and provides you easy-to-use and very flexible APIs. What’s more, QueryDSL makes your code type-safe and reusable. ScalikeJDBC is a practical and production-ready one. Use this library for your real projects. Whether you like it or not, JDBC is a stable standard interface. Since most of RDBMS supports JDBC interface, we can access RDBMS in the same way. We believe that ScalikeJDBC basically works with any other RDBMS (Oracle, SQL Server and so on). If you can access some datastore via JDBC interface, that means you can access them via ScalikeJDBC too. Recently, Amazon Redshift and Facebook Presto support JDBC interface. You can access them via ScalikeJDBC! Of course, you can use c3p0 (or others) instead of commons-dbcp though ConnectionPool implementation for that isn’t provided by default.
    Downloads: 0 This Week
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  • 13
    Scaloid

    Scaloid

    Scaloid makes your Android code easy to understand and maintain

    Scaloid is a Scala library designed to make Android app development in Scala more concise, idiomatic, and less verbose compared to using the standard Android APIs. It provides wrappers, syntactic sugar, and implicit conversions so that interacting with Android UI elements, layouts, intents, and other Android primitives feels more natural to Scala developers. For example, it offers DSL-style helpers for defining views and layouts with less boilerplate, implicit conversions to help with event listeners, and utility methods to simplify common tasks. Scaloid aims to capture the expressiveness of Scala—higher-order methods, implicit conversions, extension methods—to let Android development be more functional and succinct. It lowers friction for Scala developers targeting Android, making UI code more compact and composable while still maintaining access to full Android platform capabilities.
    Downloads: 0 This Week
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  • 14
    Shapeless

    Shapeless

    Generic programming for Scala

    Shapeless is a powerful generic programming library for Scala, enabling compile-time abstraction and manipulation of types. It provides features such as HLists (heterogenous lists), generic derivation of type class instances, dependent types, and polymorphic functions—allowing developers to write boilerplate-free, type-safe code.
    Downloads: 0 This Week
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  • 15
    Spire

    Spire

    Powerful new number types and numeric abstractions for Scala

    Spire is a numeric and algebraic library for Scala, offering type-safe, generic, and high-precision arithmetic. It introduces abstractions like Rings, Fields, and Rationals and supports specialized number types (e.g. Rational, Complex, Interval), macros, and seamless integration with Cats for abstract numeric programming.
    Downloads: 0 This Week
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  • 16
    Spray

    Spray

    Scala libraries for building and consuming RESTful web services

    Spray is a suite of Scala libraries built on top of Akka that offers a modular, asynchronous, and non-blocking toolkit for building and consuming RESTful and HTTP services. The core philosophy behind Spray is that it should act as a “library” for integration and HTTP layers, not as a full application framework—it gives you the building blocks to handle HTTP and REST but doesn’t impose heavy structure. It includes modules for low-level HTTP I/O, routing, client and server APIs, HTTP model (requests/responses), (un)marshalling, servlet adapters, and testing utilities. Its routing DSL offers expressive combinators for defining HTTP endpoints, and its testkit allows route logic to be tested in isolation (even without spinning up actors). It was popular in earlier Scala/Akka stacks but has since been superseded by Akka HTTP as the maintained successor.
    Downloads: 0 This Week
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  • 17
    Twitter Util

    Twitter Util

    Wonderful reusable code from Twitter

    Twitter Util is a collection of utility libraries used at Twitter, covering concurrency (Futures, Promises), timing, caching, I/O helpers, validation, stats collection, and Scala–Java interoperability. Designed for reliability and efficiency in high-scale systems.
    Downloads: 0 This Week
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  • 18

    Waterloo

    Java-based scientific graphics

    Java-based scientific graphics with support for Java, Groovy, MATLAB, Python, the R statistical environment, Scala and SciLab.
    Downloads: 0 This Week
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  • 19

    date-parser

    Rule Interpreter for natural date descriptions

    Date Rule Interpreter for date descriptions like 'next sunday' and 'the day before christmas'
    Downloads: 0 This Week
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  • 20
    osm4scala

    osm4scala

    Reading OpenStreetMap Pbf files.

    Scala and polyglot Spark library (Scala, PySpark, SparkSQL, ... ) focused on reading OpenStreetMap Pbf files.
    Downloads: 0 This Week
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  • 21
    scalajs-react

    scalajs-react

    Facebook's React on Scala.JS

    Scala.js React wraps Facebook React for Scala.js with a strong emphasis on type safety and functional idioms. It provides a typed virtual DOM interface, reusable components, hooks, and utilities for routing, testing, SSR, and performance profiling, all aligned with Cats, Cats Effect, and Monocle ecosystems.
    Downloads: 0 This Week
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