JPHP's documentation is based on sphinx-doc. You can always find the last version of the documentation on http://jphp-docs.readthedocs.org/.
You need to install the sphinx-doc system with Python 2.7 or 3+.
After this, install the sphinxcontrib-phpdomain and sphinx_rtd_theme extensions
via the pip or easy_install commands.
At the end, cd to the root of the docs and:
sphinx-build -b html . _build
Or you can download the last html portable version here: https://media.readthedocs.org/htmlzip/jphp-docs/latest/jphp-docs.zip