https://www.theregister.co.uk/2018/07/24/reactos_gets_stability/

Open-source Windows wannabe ReactOS took another tentative step towards usability with a 0.4.9 release aimed at stability and self-hosting.

Tweaks in this version fix the FastFAT driver to stem resource leakages, which might hit IO performance, but makes up for it in improvements to stability. Self-hosting – the ability to build ReactOS on ReactOS – also makes an appearance.