Xelem is a compact Java-library to read and write Excel files of type SpreadsheetML. It can produce sophisticated, intricate and complex spreadsheets from within any Java program. And, since the release of xelem.2.0, it can read xml-spreadsheets.
Sum-It is spreadsheet application for the BeOS.
It was orignally developed by Maarten Hekkelman (www.hekkelman.com) and later released as Free Software.
An initial release was made from Maarten's source, but development has ceased.