Java: State of (Project) Loom

They took the guys that made Quasar (Java fibers library) and hired them full time to work on this. Java already has some of the best concurrency support of any language, it just doesn't support fibers since the implementation dates back many years

Java has a history of adopting the best OSS project and making it official. Joda Time, Hibernate and JPA, all the Immutable collection stuff borrowed from Guava. I assume this will be no different.

I would not be surprised at all if Java ends up with the best fiber implementation around and convinces other languages to embrace them since "Java can't be cooler than us".

Java is doing something interesting here. They want to maintain backwards compatibility, so they're not adopting async/await first which many languages do as a stepping stone. Their goal is to make fibers appear as normal threads to old code. This would be a huge boon for existing projects, it could make existing REST frameworks and db access 5x faster overnight. Many languages can't do this because of numerous C extensions (because they're not as fast), but even big Java frameworks are typically still pure java.