OpenRGB 1.0rc1 is the first release candidate build before the upcoming official 1.0 release. This build should be considered stable, but we're looking to track down any major last-minute bugs before release. The plugin API has been updated, so if you're upgrading from 0.9 you will need to upgrade your plugins to the latest pipeline versions.

Builds for 1.0rc1 have been posted on https://openrgb.org/ as well.