For a while I've been lurking on the development of cell-mode [1], an Emacs mode created by David O'Toole. The blurb says:
Cell-mode is an object-oriented spreadsheet control for GNU Emacs. It provides a major mode for spreadsheet-based user interfaces; it can be further extended by defining application-specific Emacs Lisp minor modes which supply new cell and spreadsheet classes via Emacs’ included object system, EIEIO.
I decided to create this post because I am not sure how widely known this mode is, and I'd like to raise attention to it. Personally, I think it is an amazing idea - a magit or org-mode-like "killer app" for Emacs. It may sound like I'm exaggerating (and perhaps I am), but just off the top of my head I can think of a few really interesting use cases:
I'm sure many more use cases would quickly emerge by integrating it with other modes. If you use cell-mode or know of similar modes in this space do let me know on the comments.
Disclaimer: I have no affiliation with David O'Toole or cell-mode development, just a regular Emacs user.