Earlier this year was the Slackware 15 Alpha and Beta followed by RC1 in August . Now on Wednesday Slackware 15.0 RC2 was released.
The Slackware 15.0 pre-release change-log though did mention " we're going to have to trend more carefully for things to settle down, so consider this RC2 and a much harder freeze. A test mass rebuild was done here and there are no more "fails to build from source" remaining. "
Since the prior RC1 there has been quite a mix of package updates to flow in across the board from newer KDE packages to other open-source software package updates of recent months.
See the current change-log for a look at the latest happenings ahead of Slackware 15.0. The current Slackware ISO builds are available from the mirrors . Given how things are currently trending and the time between these test releases, it's quite likely Slackware 15.0 won't be officially christened until 2022.