Wine-staging has been discontinued as of February 17, 2018. See the official announcement for more information.
What is Wine Staging?
Wine Staging is the testing area of winehq.org. It contains bug fixes and features, which have not been integrated into the development branch yet. The idea of Wine Staging is to provide experimental features faster to end users and to give developers the possibility to discuss and improve their patches before they are integrated into the main branch. More information about Wine Staging can also be found on the wine-staging.com website.
Here are some links to the most important topics.