SkinCalc, which is completely free, features standard and advanced calculator functionality, a spreadsheet interface, and skins.

Skins make it possible to change the layout and functionality of the software, with effects that include non-rectangular shapes, user-configurable transparency and alpha channel translucency. More than 100 skins are available from the sites listed at skincalc.com, which also has instructions to create your own skins.

SkinCalc keywords: calculator, skinnable calculator, skins, skin, translucent, translucency, transparent, transparency, spreadsheet, excel, cloanto