This is genius. A markdown for spreadsheets.

I wonder whether it would be possible to extend this concept to get more powerful features, inspired by spreadsheets (and programming languages maybe). Sometimes you need more than a sum or an average, but writing out the formulas in full, repeatedly, seems like a lot of cognitive overhead.

I see in this thread that Emacs org-mode has something like it, but I'm not convinced that stuff like

    #+TBLFM: @2$4=vmean($2..$3)

matches the humane, readable, Markdown-esque approach that I'd want to use.

This is very clever. Of course, coming from Ward it's hard to expect anything less :)

Again, I'd like to plug http://www.ledger-cli.org. It's similar in spirit, with a reporting program reading a lightly formatted text file.

Reminds me of Soulver. https://itunes.apple.com/us/app/soulver/id413965349?mt=12

Calca, too. The awk script should do if you want something simpler, but I'd recommend either Soulver or Calca for their extra features.

Clever solution - technically. For trips with my friends we use a "money-pot" system where everyone pays a fixed amount into a pot before the trip and everything we do or buy together is paid out of this pot. After the trip the calculation is much easier - refund = (remaining amount / persons) ;-)

You can do those kinds of quick reports in text files conveniently in emacs org-mode nowadays:

http://orgmode.org/org.html#The-spreadsheet

I didn't know about this one. Nice!!!

http://www.splitwise.com circa 1981?

I'm very impressed. That is the shortest version of expense calculation I've ever seen.

I have written a python script back in 2007 for calculating two trips expenses: https://github.com/bernardeli/trip_money_organizer

I'm not a Python developer myself, however I was pretty happy with the result. I know it works fine, and have used few times with no issues.

I found the code itself to be beautiful, as well.

Clever pre-excel solution. In a way, ahead of its time, similar to MarkDown.

Post-visicalc though :).

Awk came after visicalc? Really? Wow.

If anyone doesn't realize Ward is the same guy who created the Wiki.

The program needn't be a shell script invoking awk--you can use a "shebang" line to make the entire thing an awk file. This will help if you use an editor which understands awk syntax (for highlighting etc.). Of course in 1981 you probably didn't have such luxuries, but today we can just remove the "exec awk", the outer quotes and $1, and put this as the first line:

    #!/usr/bin/awk -f

These days you should use Splitwise: https://www.splitwise.com/

(Not affiliated, just a happy user. And there's a nice network effect if more people use it, so more people should use it.)