They also made XHP-JS, though it seems inactive. Maybe that was the interim solution? https://engineering.fb.com/2015/07/09/open-source/announcing-xhp-js-buil

They also made XHP-JS, though it seems inactive. Maybe that was the interim solution? https://engineering.fb.com/2015/07/09/open-source/announcing-xhp-js-building-efficient-user-interface-components-with-hack-react-and-xhp/ https://engineering.fb.com/2015/07/09/open-source/announcing... https://github.com/hhvm/xhp-js https://github.com/hhvm/xhp-js