Announcing the OpenTTS project, a fork of speech-dispatcher

Luke Yelavich themuso at
Tue Apr 13 01:07:59 UTC 2010

I am writing to announce a fork of speech-dispatcher, the open source text-to-speech framework, initially developed by Brailcom as a part of the freebsoft project, The fork also includes other important components of the speech stack, including speechd-up, the connector between speakup and speech-dispatcher, and the speech-dispatcher java bindings. As you may have guessed from the subject, the fork is now called OpenTTS. OpenTTS refers to both the speech server, API and documentation, as well as the umbrella project as a whole. The other projects mentioned above have also been given new names, speechd-up is now known as OSpeakup, and speechd-java is now known as OpenTTS-java.

Why Fork Speech Dispatcher and Related Projects?

One of the fundamental freedoms granted by the GPL is the freedom to publish one's modifications to the source code of a software product.  Sometimes, such publication takes the form of a fork, in which the modified product is developed separately from the original. In this case, we've chosen to make forks of software initially produced by the Brailcom group. We'll describe our reasons for doing that below.

The Brailcom group had a great idea.  They wanted to provide a system or user-level service to control synthetic speech.  That was Speech Dispatcher. They created libraries to ease the task of communicating with that service, so that it would be possible for programmers to speech-enable their applications , simply by calling output functions provided by one of these libraries.  For several years, Brailcom actively maintained and promoted Speech Dispatcher and the software associated with it. They innovated, and the community at large was slow to adopt.

Over time, projects within the accessibility community began to embrace Speech Dispatcher.  It is now the preferred speech synthesis backend of the Orca screenreader. The Speakup screenreader can control many software-based text-to-speech engines with the help of Speech Dispatcher and a small connector program. One advantage of that strategy is that Orca and Speakup can cooperatively use the same text-to-speech engine.  The key point is that many projects have adopted Speech Dispatcher, to a greater or lesser extent.

As time passed, the tables turned. The most recent official release of Speech Dispatcher was made in the summer of 2008.  The developers began taking less and less of a role in the project.  The source code moved from a CVS repository to git in 2009.  During much of that year, active development took place in a repository hosted by Luke Yelavich.  Mr. Yelavich even produced several unofficial "release candidate" versions of Speech Dispatcher. Unfortunately, the official release process is stalled. In an effort to clarify the current status of the software, members of the community contacted Brailcom. Replies to these requests for information were somewhat non-committal.  In effect, Brailcom stated that they were interested in developing Speech Dispatcher, but they had no current plans.

That, in short, is why we forked.  Members of the open-source accessibility community need and want an actively-developed speech framework. The OpenTTS project hopes to fulfill that need by carrying forward the vision set forth by Brailcom.

The website is now live, although there is not much there at the moment. The site will be expanded in the near future to add areas for documentation, and feature specification tracking, to help developers better outline and indicate what the next release of OpenTTS will contain. You will also find a link to our mailing lists, where you can discuss OpenTTS development.

We welcome all contributors from the community who wish to help us further develope the OpenTTS framework, and encourage any interested contributors to join the opentts-dev mailing list. To get more information on this list, or other lists relating to OpenTTS, please go to We also especially welcome any Brailcom staff who wish to contribute to the project.

I plan to announce the focus for OpenTTS development over the next 6 months very soon, and will do so on the opentts-dev mailing list (see above), and the website, so please stay tuned for more information. Should you have any questions, please feel free to subscribe to the opentts-users mailing list, and ask away. Commonly asked questions will be put up on the website for all to read.

Finally, I'd like to thank Chris Brannon and William Hubbs for their hard work so far in helping get things off the ground, particularly with code cleanup and re-organisation. I would also like to thank all of those in the community who supported going ahead with the fork, you know who you are.

I sincerely hope that from here on out, we can create a text to speech framework that can rival those available for proprietary operating systems, as well as creating a framework that all application developers feel comfortable working with. Text to speech is important for more than just those with a disability, it is very useful for many other people for many different tasks. Lets give them a reason to want to use it.

Luke Yelavich
OpenTTS project lead.

More information about the Blinux-list mailing list