Introduction

Prism is the Platform-Agnostic Reader Interface for Speech and Messages. The actual expansion is a mouthful, so we just call it Prism.

Prism aims to take all the TTS and screen reader engines out there and to combine them into a single, unified library, with a single, easy to understand interface. Prism does this by being comprised of back-ends. The front-end is the C library, documented in the next section of this reference manual; back-ends are the actual text-to-speech or screen reader communication interfaces themselves. Back-ends may choose what to implement as they see fit; almost nothing is required.

Conventions

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “NOT RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.