1.scala / scalaScala 2 compiler and standard library. Scala 2 bugs at https://github.com/scala/bug; Scala 3 at https://github.com/scala/scala3scalascala-compilerscala-programming-languagescala-libraryjvm-languagesfunctional-programming+1 moreScalaAPACHE-2.015K total3.3K forks+150 starsfrom 14,385 · score 5.02
2.apache / pekkoBuild highly concurrent, distributed, and resilient message-driven applications using Java/Scalaactor-modelcloud-nativeconcurrencydistributed-actorsdistributed-systemshigh-performance+4 moreScalaAPACHE-2.01.7K total214 forks+102 starsfrom 1,561 · score 4.63
3.akka / akka-coreA platform to build and run apps that are elastic, agile, and resilient. SDK, libraries, and hosted environments.reactivedistributed-systemsconcurrencyhigh-performanceakkaactor-model+3 moreScalaOther license13K total3.5K forks+66 starsfrom 13,216 · score 4.20
4.typelevel / catsLightweight, modular, and extensible library for functional programming.ScalaOther license5.5K total1.2K forks+63 starsfrom 5,415 · score 4.16
5.lhartikk / ArnoldCArnold Schwarzenegger based programming languageScalaAPACHE-2.06.9K total294 forks+51 starsfrom 6,833 · score 3.95
6.scalaz / scalazPrincipled Functional Programming in Scalascalazscalafunctional-programmingscala-nativescalajsScalaOther license4.7K total696 forks+17 starsfrom 4,653 · score 2.89
7.galax-io / gatling-picatinnyGatling DSL extensions — feeders, profile management, transactions, assertions, Redis integration, and utility functionsgatlingperformanceperformance-testinggatling-plugindslfeeders+6 moreScalaAPACHE-2.014 total1 forks+9 starsfrom 5 · score 2.30
8.milessabin / shapelessGeneric programming for Scalascalatypelevelfunctional-programminggeneric-programmingfpScalaAPACHE-2.03.4K total520 forks+8 starsfrom 3,393 · score 2.20
9.twitter / utilWonderful reusable code from TwitterfinaglescalautilityScalaAPACHE-2.02.7K total568 forks+7 starsfrom 2,713 · score 2.08
10.monix / monixAsynchronous, Reactive Programming for Scala and Scala.js.scalamonixtypelevelfunctional-programmingreactive-programmingfp+4 moreScalaAPACHE-2.01.9K total244 forks+7 starsfrom 1,925 · score 2.08
11.softwaremill / quicklensModify deeply nested case class fieldsscalalensesfunctional-programmingScalaAPACHE-2.0852 total53 forks+7 starsfrom 845 · score 2.08
12.com-lihaoyi / fastparseWriting Fast Parsers Fast in ScalaScalaMIT1.1K total164 forks+3 starsfrom 1,132 · score 1.39
14.sparsetech / toml-scalaArchivedTOML parser with codec derivation for the Scala platformscalascala-nativetomlshapelessscalajsScalaNo license31 total10 forks+2 starsfrom 29 · score 1.10