Today, the Java Community Process posted the Proposed Final Draft of JSR 363:
https://jcp.org/aboutJava/communityprocess/pfd/jsr363/index.html.

Corresponding GitHub release tags for API are:
https://github.com/unitsofmeasurement/unit-api/releases/tag/0.9
for the RI:
https://github.com/unitsofmeasurement/unit-ri/releases/tag/0.9
and for the TCK:
https://github.com/unitsofmeasurement/unit-tck/releases/tag/0.9

Most other artifacts like unit systems, libraries or uom-demos got corresponding tags like "Public Final Draft" or "PFD equivalent" buiding upon the PFD stage JSR. All of them except demos can also be found either on MavenCentral, Bintray JCenter or both.