PEAR class for generating Excel spreadsheets. It was born as a port of the
Spreadsheet::WriteExcel Perl module to PHP. It allows writing of Excel
spreadsheets without the need for COM objects.  It supports formulas, images
(BMP) and all kinds of formatting for text and cells.  It currently supports
the BIFF5 format (Excel 5.0), so functionality appeared in the latest Excel
versions is not yet available.