typelevel/cats

Lightweight, modular, and extensible library for functional programming.

scalatest/scalatest

A testing tool for Scala and Java developers

rickynils/scalacheck

Property-based testing for Scala

milessabin/shapeless

Generic programming for Scala

scala-native/scala-native

Your favorite language gets closer to bare metal.

etorreborre/specs2

Software Specifications for Scala

scopt/scopt

command line options parsing for Scala

fthomas/refined

Simple refinement types for Scala

lihaoyi/fastparse

Writing Fast Parsers Fast in Scala

mpilquist/simulacrum

First class syntax support for type classes in Scala

lihaoyi/utest

A simple testing framework for Scala

scalapb/scalapb

Protocol buffer compiler for Scala.

argonaut-io/argonaut

Purely functional JSON parser and library in scala.

scala/scala-parser-combinators

simple combinator-based parsing for Scala. formerly part of the Scala standard library, now a separate community-maintained module

lihaoyi/scalatags

ScalaTags is a small XML/HTML construction library for Scala.

lihaoyi/sourcecode

Scala library providing "source" metadata to your program, similar to Python's __name__, C++'s __LINE__ or Ruby's __FILE__.

typelevel/discipline

Flexible law checking for Scala

typelevel/squants

The Scala API for Quantities, Units of Measure and Dimensional Analysis

outr/scribe

Practical logging framework that doesn't require any other logging framework and can be completely configured programmatically.

typelevel/machinist

Spire's macros for zero-cost operator enrichment