It is still supported and used. It's been my distro of choice for several years.

if you choose the current or the stable stream, last update was yesterday:

• http://www.slackware.com/changelog/stable.php?cpu=x86_64
• http://www.slackware.com/changelog/current.php?cpu=x86_64

If you need help, there are many users that can help you here https://www.linuxquestions.org/questions/slackware-14/