Today, the Java Community Process posted the Public Review of JSR 363:
https://jcp.org/aboutJava/communityprocess/pr/jsr363/index.html.

Corresponding GitHub release tags for API are:
https://github.com/unitsofmeasurement/unit-api/releases/tag/0.8
for the RI:
https://github.com/unitsofmeasurement/unit-ri/releases/tag/0.8
and for the TCK:
https://github.com/unitsofmeasurement/unit-tck/releases/tag/0.5

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