EtherCalc - EtherCalc is a web spreadsheet.
Aspose.Cells for Cloud - Aspose.Cells for Cloud is a REST based API for processing spreadsheets in the cloud.
FlexiSheet - FlexiSheet is a multi-dimensional spreadsheet in the spirit of Lotus Improv.
SSuite Axcel Professional Spreadsheet - This powerful and professional spreadsheet has all the tools you need to calculate, analyse, summarize, and present your data in numerical reports or colourful graphics.
LibreOffice - Calc - LibreOffice Calc is the spreadsheet program you've always needed. A fork of OpenOffice.
Simple Spreadsheet - Simple Spreadsheet