The latest version of Slackware can be downloaded from Softpedia
Slackware Linux, a complete 32-bit multitasking "UNIX-like" system that is currently based around the 3.10 Linux kernel series, is now at version 14.1 RC1.Slackware Linux 13.37 has been for a long time in development, but the 14.x branch seem to be advancing a lot faster than the previous versions.
“And with this batch of updates and fixes (clearing the rest of the important stuff from the TODO list), we have arrived at Slackware 14.1 release candidate 1! Please test and report any remaining issues,” reads the official announcement.
The distribution is now based on Linux kernel 3.10.16, and a lot of packages have been updated. Download Slackware Linux 14.1 RC1 right now from Softpedia.
Remember that this is a development version and it should NOT be installed on production machines. It is intended for testing purposes only.