[Matti]

Far from identical, but along similar lines: http://treesheets.com/

"It's like a spreadsheet, immediately familiar, but much more suitable for complex data because it's hierarchical. It's like a mind mapper, but more organized and compact. It's like an outliner, but in more than one dimension. It's like a text editor, but with structure. "

You can nest spreadsheet-like cells within cells within cells within cells.. and zoom in and out between the various levels of nesting.

For Windows and Ubuntu, with a beta for Mac OS X available.

[uniclaude]

That's great, definitely bookmarked.

An in-browser, collaborative version would be a serious killer app.

[anigbrowl]

Interesting. Also, great to have the screenshots up front.

[sweetdreamerit]

seems nice, but I have a question: can it import - export to other formats? Latex, markdown, csv ....

[Matti]

You can export/import views as XML or CSV. The generated XML is UTF-8 encoded and it only has three element types in total for the cells and rows so the structure of the file isn't complicated at all.

[ptrotter]

Treesheets is an awesome way of structuring ideas and materials. As Matti said, the XML output from TreeSheets is easy to parse and convert for other uses. Basic HTML export is also provided as a simple means of sharing sheet data. Since TreeSheets is an open source project - it is possible to extend these areas of functionality to meet your own workflow needs and the code is easy to follow and fun to work with.