Apache PekkoFull replacementBuild highly concurrent, distributed, and resilient message-driven applications using Java/ScalaFork of Akka 2.6 under Apache-2.0, with packages renamed to org.apache.pekko.Official migration guide ↗LanguageScalaLicenceApache-2.0Stars1.6kLatestv1.7.1Last push2026-10-05
Vert.xPartialVert.x is a tool-kit for building reactive applications on the JVMVerticles exchange messages over an event bus, an actor-like model without Akka's supervision hierarchies.LanguageJavaLicenceOtherStars15kLatest5.2.0Last push2026-10-06