Slackpkg-slamd64 is a project mainly written in Shell, it's free.
Slackpkg ported to Slamd64
Porting Slackpkg, the Slackware remote package manager, for use on Slamd64 is non-trivial. With this in mind, here is a tree containing my working ported tree, and also a tool to take a standard slackpkg package from Slackware and automatically port it for use on Slamd64.
As of this writing, this script is known to work on Slackpkg 2.71.2.