The term "Custom TclKit" is obsolete - it is now called a Starpack, please visit that page for more info.
A Starpack is a single (platform specific) executable file containing both TclKit and a Starkit. They are useful when you want to deploy a single executable for an application. Starpacks can be built on any platform supporting TclKit, for any platform supporting TclKit.
Creating a Starpack is described at [L1 ].