The EmacSpeak by T. V. Raman <raman@cs.cornell.edu> software package provides speech output for Emacs, and includes "speech servers" for the DECtalk speech synthesizers.
The package emacspeak-ss provides servers for several additional synthesizers:
DoubleTalk PC and AT from R. C. Systems
Braille 'n Speak, Type 'n Speak, and Braille Lite from Blazie Engineering
Accent SA
Apollo 2, JUNO, and JUNO-sp from Dolphin.
Spanish ciber 232
Spanish ciber 232 Plus
Spanish PC Hablado notebook
None of these programs are normally run by the user directly. Instead, they are run by Emacs. That is: Emacs runs the emacspeak code, which executes Tcl, which interprets the server code. This approach is too closely "wired" to usage with Emacspeak, so it may not be used for our general purposes.
This does not mean, that these servers are compleetly a bad idea and we can not use them. Thanks to the author Jim Van Zandt), we can learn from the sources and write the output driver modules for Speech Daemon (emacspeek-ss is GPL).
Bart Bunting is working on a speech server using the MBrola speech synthesis.
The problem of speaking X Window applications can be devided into several subproblems.
Window managers
Desktop managers
Widget toolkit libraries
Applications themselves
Several windowing toolkit libraries take speech support into a focus the last few years. These are:
GTK+ (Gnome Accessibility project)
wxWindows
Java AWT
FOX toolkit