XLSX Support

Features that are already supported are, cell merging, get/set cell data, basic styles and range operations like copy cells, insert row/column, clear cells, etc.

Objects that are not supported like autofilter and VBA macros will however be read and preserved without loss of fidelity.

Now that Excel 2007 lets you insert more than 65,000 rows of data, you can do the same with XlsIO.

You can also open the xlsx files and resave it in Excel 2003 file format and vice versa.