A free and open-source software tool is presented that facilitates the analysis and the visualisation of data in basic life science. Daniel's XL Toolbox is an add-in for the Microsoft Excel^® spreadsheet software. It enables scientists to store their data in one place and obviates the need to use separate tools for the analysis and presentation of the data. The Toolbox offers analysis of variance with post hoc multiple comparison testing and linear correlation and regression analyses. It can apply error bars to the graphs automatically, and style the graphs in a way suitable for publication. The graphs can be exported in high resolution to TIFF, PNG, as well as to EMF file types. Finally, the Toolbox offers several work flow and productivity features such as automatic time-stamped backups, transposition assistant, worksheet management, and much more. The Toolbox is available at http://xltoolbox.sourceforge.net.