Sheetster is the open source web spreadsheet designed from the ground-up to be an extensible application UI and services component which can be easily embedded into applications of any type.

Sheetster Integration methods include but are not limited to:

standalone usage as a document/spreadsheet collaboration app server
embedded spreadsheet editor within existing CMS and document repositories
re-use of business logic contained in spreadsheets by accessing spreadsheet formulas as REST web services
used in conjunction with rich spreadsheet templates as a reporting and data analysis tool
used as a service through Sheetster.com
creation of portals and hybrid web applications requiring a combination of client-side AJAX and server-side REST
addition of enhanced custom functionality through creation of custom REST Plugins