LibreOffice - Calc - LibreOffice Calc is the spreadsheet program you've always needed. A fork of OpenOffice.
CubeWeaver - CubeWeaver is a collaborative multidimensional spreadsheet software especially useful for financial planning, financial modelling, budgeting, reporting and what-if simulations.
Resolver One - Resolver One is a program that blends a familiar spreadsheet-like interface with the powerful...
XCubes - Multidimensional spreadsheet for financial simulation, planning, reporting, marketing analysis etc.
Excel Formula Beautifier - Beautifies Excel to JavaScript/JSON format.
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.