The latest documentation can be found here: http://www.maxback.io/docs/latest/
The binaries of all MaxBack VSS Writer versions can be found here:
Remarks about the download page:
The current - stable - version is automatically selected.
In the selectbox "Versions" you can switch to an older or newer version.
There is also an alternative download available for systems without internet connection. In this case, however, the .NET Framework 4.71 or higher must already be installed.