Google Sheets - Synchronizing, online-based word processor, part of Google Drive.
Microsoft Office Excel - Microsoft Office Excel is a commercial spreadsheet application.
EtherCalc - EtherCalc is a web spreadsheet.
Gnumeric - Gnumeric
LibreOffice - Calc - LibreOffice Calc is the spreadsheet program you've always needed. A fork of OpenOffice.
DataTables - DataTables is a plug-in for the jQuery Javascript library.