A Microsoft Excel add-in wiht a collection of easy to use free tools and utilities (built with powerful Excel VBA macros), all accessible from the added Extools menu on Excel's menu bar. (For Excel 97, 2000, 2002, 2003). Extools is compatible for MS Excel 2007 but runs in "compatibility" mode. If you have Excel 2007, you can get Extools RX, which is specially designed for Office 2007's new interface.