Open Source, web based spreadsheet app with formulas

Question

I am looking for an open source spreadsheet application to stick into my web page. The most important feature I am searching for is formulas. Specifically, I need to be able to put in a cell which calculates the total of the contents of other specified cells.

I've found some basic examples like Nitobi and ExtJs Extender, but they don't allow any calculations.

Is this a lost cause, or is the perfect spreadsheet app out there, waiting for me to find it?

Answer 1

I just found something that looks like exactly what I'm looking for: Simple Spreadsheet.

Not only does it do functions, but it does graphing as well, among many other things.

It is written in Javascript, HTML, CSS and PHP, and is open-source under the GNU GPLv2 License.