[zdw]

Whenever accounting comes up in geek circles, it's worth mentioning ledger and similar systems it inspired which use plain text files to implement double entry accounting:

https://www.ledger-cli.org

I used this system for years as a consultant - it's also pretty easy to extend - I did this using the Python API to implement an arbitrary RPN calculator on top of it:

https://github.com/zdw/ledgercalc

[dugmartin]

More info here on other like-minded systems like hledger and Beancount: https://plaintextaccounting.org/

[rthomas6]

I use this, except I use Beancount. It's written in Python and is easier to write your own little extensions. There's also a GUI called Fava that goes along with it and is really good.

[fabianhjr]

I have tried several (like https://hledger.org/ ) but would prefer some REA/ValueFlows accounting software.

[NoboruWataya]

Also GnuCash, which I feel requires no elaboration on HN as it is so frequently its own topic of discussion.