As3xls is a project mainly written in ACTIONSCRIPT and PHP, it's free.
Fork of as3xls with bugfixes (unmaintained)
This is my fork of as3xls — an Excel library for Actionscript 3. Here I've fixed a number of bugs in the XLS-reading portions of the code.
At the moment I have no need for the XLS-writing parts, so won't be maintaining them. I'm happy to receive patches though!