Quantrix is already a better excel and look how well they're doing for themselves (or not).
But seriously: take a gander at quantrix, rip off its features, slap yourself on the back for innovating, and go home.
Edit: the above is perhaps a bit too snarky to be helpful.
As a "power spreadsheet user" I moved on from excel to quantrix; this is something I can get away with b/c I'm not stifled with a closet full of legacy, mission-critical excel spreadsheets.
Quantrix is pretty much at the sweet spot of spreadsheet functionality: it's possible to imagine a more-powerful and more-general-purpose tool, but taking it even a little further would turn it into something not really a spreadsheet any more...you'd wind up back at R.
You'll find in Quantrix a mature, well-thought, and all-around "better excel".
But seriously: take a gander at quantrix, rip off its features, slap yourself on the back for innovating, and go home.
Edit: the above is perhaps a bit too snarky to be helpful.
As a "power spreadsheet user" I moved on from excel to quantrix; this is something I can get away with b/c I'm not stifled with a closet full of legacy, mission-critical excel spreadsheets.
Quantrix is pretty much at the sweet spot of spreadsheet functionality: it's possible to imagine a more-powerful and more-general-purpose tool, but taking it even a little further would turn it into something not really a spreadsheet any more...you'd wind up back at R.
You'll find in Quantrix a mature, well-thought, and all-around "better excel".