This is the release candidate for the next major version 1.6 of Roundcube webmail.
It includes a small number of improvements and fixes in comparison to the beta release. For more information read the changelogs.
https://github.com/roundcube/roundcubemail/releases/tag/1.6-rc https://github.com/roundcube/roundcubemail/releases/tag/1.6-beta
We believe it is production ready, but we recommend to test it on a separate environment. And don't forget to backup your data before installing it.
ps. This is the first time I created a Roundcube release, I hope that all works as it should.
Cheers, Alec