Altair SLC can read Excel spreadsheets, but can it read OpenDocument spreadsheets (*.ods)?
Since installing OpenOffice.org/LibreOffice for office documents I have only had to use Excel files on client sites. OpenDocument spreadsheets (*.ods) are compressed XML file collections similar to *.xlsx files, so reading them should not be a major problem. In fact I wrote a paper in 2004 on how a SAS program could read a StarOffice Calc file "Help, I’ve Received a Spreadsheet File from StarOffice Calc…..!", and have since tweaked that code a little to read *.ods files (see my book "SAS Programming Experiences: A How-To Guide from a Power SAS User" for details).
All referenced items are available on my blog site.