Create Excel chart from spreadsheet on Un*x?

I'm using Spreadsheet::WriteExcel::FromDB::Query to create spreadsheets
directly from a Mysql database. It's very cool.

Now I'd like to obtain a chart, or graph, from the spreadsheet. It's
easy to do with a few Excel keystrokes; but I want to do it
programmatically.

I gather that if I were to get Perl running on a Windows box I could use
Win32::OLE to control Excel from within Perl. But then I'd have to use a
Windows box, learn OLE/Active-X, etc. I'd rather not go down that path
if I don't have to.

Is there a way for me to make a chart from a spreadsheet on a Un*x box?
Or, is there perhaps some open-source spreadsheet that can be used in
place of Excel?