Plain text accounting with Beancount

Plain text accounting is the idea of managing personal finances (or perhaps a small business, or club, or whatever) using a scriptable, command-line-friendly open source accounting software keeping all related data in plain text files which are easy to version control e.g. with git.

This is an alternative to using something like e.g. Intuit QuickBooks, Zoho Books, Xero, etc. or even just whatever one of your banks offers you built-in.