It’s finally out…read about it here: https://www.haiku-os.org/get-haiku/r1beta4/release-notes/

Versioning: Add BETA_4 and PRE_BETA_5 version constants. UPDATE: Even closer… docs/develop: Add missed item to the branch steps and combine the last two. Enable “HAIKU_OFFICIAL_RELEASE“ UPDATE: R1/Beta4 is now in ‘testing’…if you can help, grab it here and send your feedback… https://discuss.haiku-os.org/t/help-wanted-haiku-r1-beta4-boot-hardware-testing/12658

Good news for the project…you can read about it on their site: https://www.haiku-os.org/news/2021-08-25_hiring_waddlesplash/