PHP code to write excel spreadsheet with multiple workbooks

Hi all, I have a linux based web app which prints an html screen of results. My users really want Excel spreadsheets with the same results. There is a PEAR application which does this, but from the PEAR description it seems to be pretty buggy (65 open bugs, average days open 616 days) and dated. My spreadsheets will be somewhat simple. They will have multiple workbooks and could be as large as 10000 rows spread out over 100 workbooks (Bigger than the code can handle, according to one of the open bug reports). No colors, no formulas, no hyperlinks. I've checked the archives and found an example which shows me how to write the results of an SQL (MySQL, I am using postresql, but the example will still work) into a very simple Excel spreadsheet with just one table of results. Is there a way to get a php program to generate a spreadsheet with multiple workbooks? Thanks Mary