See home page of beancount repository for project details:
https://github.com/beancount/beancount/blob/master/README.rst
The latest documentation is available in Google Docs at: http://furius.ca/beancount/doc/index
A frequently updated copy of the documentation is also convert to Markdown and available at: https://beancount.github.io/docs/.