Slackware is just another Linux distribution. Their web site is
www.slackware.com.
Basically, now, with Linux distributions, there are two major strategies:
- Distributions that use graphical configuration tools, complex startup scripts, e.t.c., to "facilitate" administration and look more attractive in the eyes of corporate clients and inexperienced end-users.
- Distributions that are sort of the complete opposite of type A, whose startup scripts are simple, easy to figure out. These distributions are geared towards intermediate/experienced users who like to "get their hands dirty".
Examples of distributions of type A are RedHat and Mandrake. Examples of type B distros are Slackware and Debian.
Personally, the first time I tried Slackware, I had a "love at first sight"
experience. I absolutely loved it! I still use it. However, I would not recommend Slackware for production environment, unless the sysadmin really know what he/she is doing. On top of that, RPM is quite possibly the most popular packaging format nowadays (for binaries), and RedHat/Mandrake-optimized RPM packaged binaries are by far the most popular.
In the end it all boils down to your preferences... I think that a Linux distribution is like ... clothing. At first you may start off by using RedHat or Mandrake, and if you become more interested in the stuff "under the hood", you may wish to "challenge" yourself by trying out a distro like Slak or Debian.
I say it's a matter of taste and style.