A pure PHP library for reading and writing spreadsheet files
Google Sheets Python API
PowerShell module to import/export Excel spreadsheets, without Excel
The free and Open Source productivity suite
A standalone, portable Ada package for producing Excel spreadsheets
Library modules for creating ODF documents.
stylefmt is a tool that automatically formats stylesheets
C++/C library to construct Excel .xls files in code.
palo olap open office calc plugin for data analysis
an embeddable spreadsheet for your web application