This is the beancount filetype for Vim. Includes highlighting and some basic functions.
I suggest Vundle or Pathogen, but you can also just copy all of the files into the appropriate places inside your '.vim' directory.
Syntax highlighting and indenting.
Completion: Type Ex:Oth followed by ^X^O to get Expenses:Donations:Other
(provided that you have opened an account with that name).
Use :make to run bean-check and load errors in the quickfix window.
The AlignCommodity command lines up all your decimal points.
For full details, see doc/beancount.txt.