What it is
The aim of this extension is to allow Tcl developers to use attractive Mac styled widgets, knowing they'll be rendered appropriately on other platforms using Tile and Tk fallbacks.
It's an extension which would be used in conjunction with Ttk/Tile rather than replacing it, and shares the overall goal of being able to use one command and have it look platform native where-ever it's run.
Users of the Python language report that TclMacBag is "particularly easy to install" using Tkinter.
What it isn't
TclMacBag is written entirely in Tcl and isn't a hook into any Mac OS X APIs or libraries.
While TclMacBag does allow some widgets intended for the Mac to be used on other platforms using the -force yes option, providing Mac widget lookalikes for all widget types on other platforms is not a priority for this project.
Latest version
Version 0.13, released on 2008-05-05. Features: DDialog plus various fixes.
Development state
TclMacBag is now mostly feature complete. A few new widgets are still being added here and there, but, the main push is over. The conversion of the remaining TclMacBag widgets not using Snit is also on the cards.
Counter balancing this project are recent welcome pushes for progress on Tile on Aqua and a recently announced project to update Tk from Carbon to Cocoa.