I'm looking for an open source, command-line tool to convert files from the old, binary Excel ".xls" format to the new (Excel 2007) Open XML .xlsx, without Excel installed, on a Windows PC.
Ideas?
Edit: Open source is strongly preferred, but free for commercial usage is ok too.
Edit: Additional software, such as Excel Viewer, can be installed on the system, as long as open/free for commercial usage.
