puniverse/quasar

Health v2 · maintenance only

Flags: no_license

Adoption not part of the score

4551 stars · 560 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

Quasar is a JVM library providing lightweight threads (fibers), Go-like channels, and Erlang-like actors for Java and Kotlin, using bytecode instrumentation via a Java agent. It enables high-performance asynchronous and concurrent programming with an actor model, supervision, and clustering support.

Use cases

• run millions of lightweight threads on the JVM
• build Erlang-style actor systems in Java or Kotlin
• use Go-like channels for communication between concurrent tasks
• write blocking-style asynchronous code without callback hell
• build fault-tolerant concurrent applications with supervisors and hot code swapping
• cluster actors across JVM nodes

When to choose

• you need lightweight concurrency on older JVMs without virtual threads (pre-JDK 21)
• you want an Erlang/Akka-style actor model tightly integrated with fibers and channels
• you are maintaining an existing Quasar/Comsat/Pulsar codebase

When to avoid

• you are on JDK 21+ where native virtual threads (Project Loom) are available
• you want a actively developed library with a large community
• you cannot add a -javaagent instrumentation flag to your JVM launch
• you need a general-purpose distributed data grid (use Galaxy or other IMDGs instead)

Facets

library · maturity maintenance

concurrency message-queue streaming developer-tools microservices jvm cross-platform fibers actors channels lightweight-threads erlang-style go-style-channels kotlin clojure real-time

Member repositories

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