Paratext 9 version numbering works like Paratext 8 numbering – 9.0.x.y
If x is between 1 and 49, it is an alpha. Alpha versions are for early adopters only and are usually not fully featured or fully functional. They should not be used with live project data.
If x is Between 50 and 99 it is a beta. Beta versions are more functional, more feature-complete and stable than an alpha and may be appropriate to use with live projects. Sometimes a beta is offered as a “release candidate” to indicate it is a relatively stable beta version. Release candidates are the final beta versions before stable release versions.
If x is 100 or over, it is a full stable release. For example, 9.0.100.1 or greater.
The current version can be downloaded here: https://paratext.org/download/currentversion/