Slackware Linux is a packaged distribution of the Linux operating system, which is free and open source.
With Ubuntu getting all the headlines in open source world, you kind of have to see Slackware as the “anti-Ubuntu”. There is no package management system, the installer is text-only, and you’ll be doing lots of command-line work. It has a “do-it-yourself” feel to it. And beyond that, the system is highly conservative – Slackware doesn’t update a package until it’s been through extensive beta-testing. So why would anyone want to use it? The benefit of Slackware is that it is reliable, stable, and powerful. Everything you would want to do with a system can be done from Slackware, where other distros break down because they weren’t set up to handle the power-user. The saying goes that when you learn Ubuntu, you learn Ubuntu; but when you learn Slackware, you learn Linux!