This document summarizes a presentation about building RESTful applications using PHP. REST (Representational State Transfer) is a software architectural style that uses HTTP verbs to manipulate resources. The presentation covers the six constraints that define REST - client-server separation, statelessness, cacheability, uniform interface, layered system, and code on demand. It provides tips for implementing REST in PHP like using the header() function, determining the request method, and encoding/decoding JSON. Questions from the audience are answered at the end.