What style of RPG program can communicate with PHP?

What style of RPG program can communicate with PHP?
Pass a result set back to the PHP application?

We are writing a Customer Relationship Management (CRM) application in
agnostic PHP (not the ZEND optimized for IBM i)

All of the CRM-specific tables are physical files on IBM I in our CRM
library.

Substantial portions of the CRM application will join to our JD Edwards
World ERP at release A92 for information.
e.g. Retrieve from F42* files containing Sales history.
e.g. Validate postal codes against F0117 Address Book file
(exist/NotExist CHAIN)

e.g. provide a JDE# to retrieve a name from F0101 Address Book
e.g. Scrub and Edit some CRM data entry against various UDCs in F0005
User-Defined-Codes.

I am willing to write some RPG programs that our web guy could use as
program calls so that he doesn't need to do everything with SQL
statements, however, I do not know style of RPG program he could use.