Scala3

Judgement

What it is

Developer tool

What it does

The Scala 3 compiler, a JVM language combining object-oriented and functional programming.

Adopt it when

Your team uses the JVM and wants a strongly typed functional language, or uses Spark or Akka-based stacks.

Watch out

Migration from Scala 2 and library compatibility still cause friction.

Ready for

Production-ready

Runs as

Command line

Built with

Scala and Java

How established

Established: started 14 years ago, latest release 3.3.9.

What the license allows

You can build it into a product you sell, as long as you keep its copyright notice.

Judged on 2026-11-03 from the project's README and GitHub data. The license and age lines are worked out directly.

Built from

Follow it down: Scala3 → JDK → LLVM project → runs on a microchip

How compilers were built, back to punched paper tape

Built on Scala3: 8 projects

1. 1
   Neo4j neo4j

   Graphs for Everyone

   Building block Production-ready Your queries are mostly about relationships several hops deep, which are awkward in SQL.

   ★ 17k GPL-3.0 Java Active, pushed 11 days ago
2. 2
   Playframework playframework

   The Community Maintained High Velocity Web Framework For Java and Scala.

   Framework or platform Production-ready You maintain Play applications or want a Scala-friendly full web framework.

   ★ 13k Apache-2.0 Scala Active, pushed 4 days ago
3. 3
   Snowplow snowplow

   The leader in Customer Data Infrastructure

   Complete system Production-ready A data team wants full ownership of granular event data in its own warehouse for analytics and modelling.

   ★ 7k Apache-2.0 Scala Active, pushed 14 days ago
4. 4
   Docspell eikek

   Assist in organizing your piles of documents, resulting from scanners, e-mails and other sources with miminal effort.

   Complete system Usable You want a paperless archive with stronger automatic metadata suggestions and can run a JVM service.

   ★ 2.3k AGPL-3.0 Elm Active, pushed 7 days ago
5. 5
   Sharry eikek

   Sharry is a self-hosted file sharing web application.

   Complete system Production-ready You need both to send large files out and to receive files from clients or partners on your own server.

   ★ 1.4k GPL-3.0 Elm Active, pushed 5 days ago
6. 6
   Play-pac4j pac4j

   Security library for Play framework 2/3 in Java and Scala: OpenID Connect, SAML2, CAS, OAuth, LDAP, JWT...

   Integration Production-ready You build on Play and need multiple authentication protocols.

   ★ 414 Apache-2.0 Java Active, pushed 8 days ago
7. 7
   Izanami MAIF

   Izanami is a centralized versatile feature flag solution, well suited for micro service architectures.

   Complete system Usable You want a self-hosted flag server and are comfortable with a Scala and Postgres stack.

   ★ 206 Apache-2.0 Scala Active, pushed today
8. 8
   Space Cloud spacecloud-io

   Open source Firebase + Heroku to develop, scale and secure serverless apps on Kubernetes

   Framework or platform Experimental Only to study its design; the maintainers themselves point users to Hasura or WunderGraph instead.

   ★ 4k Apache-2.0 Go Quiet, pushed 2 years ago

Open-source alternatives to Scala3

1. 1
   Go golang

   The Go programming language

   Developer tool Production-ready You build backend services or command-line tools and value simple code, fast builds and single-binary deploys.

   ★ 140k BSD-3-Clause Go Active, pushed today
2. 2
   Rust rust-lang

   Empowering everyone to build reliable and efficient software.

   Developer tool Production-ready You need C-level performance with memory safety, for systems software, CLIs, services or WebAssembly.

   ★ 121k Apache-2.0 Rust Active, pushed today
3. 3
   TypeScript microsoft

   TypeScript is a superset of JavaScript that compiles to clean JavaScript output.

   Developer tool Production-ready You write JavaScript projects of any size and want static types and better editor tooling.

   ★ 112k Apache-2.0 Go Active, pushed today
4. 4
   CPython python

   The Python programming language

   Developer tool Production-ready You write Python, or need to build, embed or contribute to the interpreter itself.

   ★ 78k See repository Python Active, pushed today
5. 5
   Swift swiftlang

   The Swift Programming Language

   Developer tool Production-ready You build iOS or macOS apps, or want Swift on Linux servers.

   ★ 71k Apache-2.0 Swift Active, pushed today
6. 6
   Kotlin JetBrains

   The Kotlin Programming Language.

   Developer tool Production-ready You build Android apps or JVM services and want a more concise, null-safe alternative to Java.

   ★ 54k See repository Kotlin Active, pushed today
7. 7
   Julia JuliaLang

   The Julia Programming Language

   Developer tool Production-ready You do scientific computing, simulation or numerical work where Python is too slow and C is too painful.

   ★ 49k MIT Julia Active, pushed today
8. 8
   Php-src php

   The PHP Interpreter

   Developer tool Production-ready You build or host PHP applications, or need to build PHP or its extensions from source.

   ★ 42k BSD-3-Clause C Active, pushed today