I see the following downloads for Mac and Linux:-
Download Audacity macOs DMG - 34.11 MB | version: 2.2.0-beta-20170901 | SHA256 signature
Download Audacity Linux source - 28.38 MB | version: 2.2.0-beta-20170901 | SHA256 signature
But nothing that says it’s suitable for use on Windows 10 (64 bit). Am I missing something???
There is a “nightly build” of Audacity 2.2.0-beta-26Sept17 here: https://www.fosshub.com/Audacity-Windows-Nightlies.html
This ZIP package does not include the manual. The development manual may be viewed on-line here: http://alphamanual.audacityteam.org/man/Main_Page
Please note that alpha / beta / nightly builds are not intended for production work as they are not fully tested. They are intended for testing purposes only.