Vert.x, virtual threads
contributor, 2026
The Eclipse Foundation’s reactive Java toolkit, running about three times faster on virtual threads. It returns immediately when the work it was asked to wait on has already completed, rather than parking a thread.
Vert.x is the Eclipse Foundation’s toolkit for building Java services that hold a lot of connections at once, and its virtual thread support parked a thread to wait for work whenever it was asked to, including when the work had already finished and the answer was sitting there. Returning the available answer directly takes about a threefold slowdown out of applications built on it, and Vert.x ships this behaviour in 5.1.3.