Suppose you have a spreadsheet tracking project deadlines. If you use NOW(), every time you enter data, change a format, or just scroll through your sheet, Excel will recalculate the formula.

Excel conditional formatting made easy! Learn formulas, advanced techniques, and troubleshooting tips to enhance your data ...

It isn’t news that [s0lly] likes to do ray tracing using Microsoft Excel. However, he recently updated his set up to use functions in a C XLL — a DLL, really — to accelerate the Excel rendering.