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.
Resolver One - Resolver One is a program that blends a familiar spreadsheet-like interface with the powerful...
EtherCalc - EtherCalc is a web spreadsheet.
Excel Formula Beautifier - Beautifies Excel to JavaScript/JSON format.
Keikai - Effortlessly Build Spreadsheet-driven Web Apps
FlexiSheet - FlexiSheet is a multi-dimensional spreadsheet in the spirit of Lotus Improv.