Slackage Management, Baby!
There are those who say that Slackware Linux doesn’t really have a package manager. BAH! I say. It has two package management systems, actually.
The first is the older of the two. It’s good ol’ pkgtool. The rumor that Slack has no package manager is baloney. pkgtool is an outstanding little package management tool that serves its purpose wonderfully. The other rumor that pkgtool has no dependency checks is true, though. Slackware assumes you have half a brain and can determine which dependencies you need to fulfill to install Jumpin' Joe's Majong Marathon.
From the command line, you can installpkg, removepkg, or upgradepkg… easy-peasy, folks!