With Excel-DNA you can make native (.xll) add-ins for Excel using C#, Visual Basic.NET or F#, providing high-performance user-defined functions (UDFs), custom ribbon interfaces and more. This project ...

Microsoft's spreadsheet program can do way more than you might realize. These are the hacks and tricks you need to know.

The Draw tab is not on Excel's ribbon by default. Learn how to enable, add and use the Draw tab and the various drawing tools in Excel.

To fix an Excel spreadsheet not adding up correctly, check the SUM function's syntax and make sure there aren't any text format cells in the sheet.