We initially partnered with Jeppers to develop a Spreadsheet component to Tiki. Cameron Zemek has informed me that won't be developing Jeppers as originally thought.
Below is Jeppers related information for "historical" value.
Jeppers aims to be a full featured spreadsheet application written in 100% pure Java. Additionally it strives to provide a lightweight spreadsheet component that is flexible and reusable.
Please see: TikiSheetDev
We have forged a partnership with the Jeppers project. Here is a demo