Kaleidoscope 2.0 (known as K2) was a huge step forward in interface customization. In addition to running old Kaleidoscope schemes faster, more reliably, and with less RAM, version 2.0 offered non-rectangular windows, enhanced menus, background patterns, double-headed scrollbars, tabs, sliders, cursors, and many other enhancements.
In version 2.3, Kaleidoscope offered enhanced menu effects (in schemes that support them), including transparency and extended borders with eight-bit masks. For transparent menus in other schemes, you must use Power Windows. This version fixes many bugs and adds better compatability with other programs. To view all changes, click here.