crackxls2003 breaks the encryption on Microsoft Excel and Word 97/2000/XP/2002/2003 files which have been encrypted using the RC4 method. These files are encrypted using a 40-bit-long key. It will not work on files encrypted using versions later than 2007 or versions 95 or earlier, or if a non-default encryption method was used.
Aspose.Cells for JasperReports allows you to exports reports from JasperReports and JasperServer in Microsoft Excel spreadsheet (XLS) format. It is provided as a single JAR file that can easily be deployed on machines running JasperReports or JasperServer. It exports Excel charts as editable charts rather than static pictures so that they can be edited manually in MS Excel.
Gnumeric is a powerful and easy to use spreadsheet using GNOME. Its goal is to provide a full featured spreadsheet and a smooth migration path for people and organizations currently using proprietary applications. It provides more sheet functions and greatly improved accuracy when compared to Microsoft's Excel. A plugin system lets you extend Gnumeric, adding functions, I/O formats, and real time data capabilities. The existing Python, Guile, and Perl plugins let you define complex functions. Gnumeric is capable of reading and writing MS Excel (XLS and Office Open XML), and reading Lotus, Applix, Quattro Pro, OpenCalc (ODF), XBase, DIF, SYLK, HTML, Psion, MPS, oleo, sc, misc. text formats, and its native XML. It can also generate Latex, HTML, and others.
MonteCarlito is a free Excel-add-in (Windows and OS X) to do Monte-Carlo-simulations. It features statistical analysis of simulation runs (mean, median, standard error, and skewness), histograms, direct output to an Excel spreadsheet, and a high-speed simulation mode with minimized windows.