Open Source JavaScript Spreadsheet Software

PHPEditTable is a class which mimics a simple spreadsheet behaviour. It handles cell formatting as well as math expressions based on cells' addresses parsing. Works with complicated formulas, setting properties on cell/row/column/range/sheet level.

Sheetster is a web-based spreadsheet editor and viewer. It can import and export the XLS and XLSX file formats and nearly the full range of Excel formula functions are supported. Most basic features are implemented as well as some of the more advanced ones. The user interface is written entirely in JavaScript and its server-side API is pure Java based on the OpenXLS spreadsheet engine. Neither the client nor the server needs Excel or any browser plugins. Sheetster is primarily intended for developers who want to integrate spreadsheets into their web applications. Towards that end it provides a server-side API for document storage connectors and a rich REST API for manipulating open spreadsheets. It can also be deployed stand-alone by a website administrator to provide spreadsheet editing with a rudimentary CMS.

GelSheet is a free and open source web spreadsheet that allow users to create, edit and export in many formats your everyday work. It's intended to run either standalone or integrated within another web tool. It was born as a part of Opengoo web office