Common Public License (CPL)

Olaf Jan Schmidt ojschmidt at
Sat Mar 4 11:44:59 GMT 2006

Hi George!

Providing a stub library to circumvent the (L)GPL license does not work, no 
matter how the stub library is licensed.

In KDE4, we will replace large parts of kttsd with SpeechDispatcher, so the 
KDE license policy won't apply, but the problem will remain. You cannot use 
Epos or espeak in the same process as the IBM speech engine, because the 
license of proprietary libraries is incompatible with GPL-licensed speech 
engines. You also cannot link to a proprietary library from LGPL-licensed 
code (only the other way around), which means that the gnome-speech 
architecture has legal problems.

SpeechDispatcher keeps the various speech engine drivers in separate processes 
and avoids linking proprietary speech engines and GPL-licensed speech engines 
together. This is the only correct way to do it.

As a short term solution for KDE 3, it is possible to let kttsd call a command 
line application that uses the IBM voices. This can be done via the kttsd 
"command" plug-in. Or IBM could provide a GPL-licensed kttsd plugin that 
calling the command line utility to synchronise text, to request the 
available voices or to set additonal parameters.

For KDE4 we plan to do the following:

a) We define a standard API for the drivers of speech engines.

b) SpeechDispatcher is ported to the new API.

c) We port kttsd to use SpeechDispatcher.


Olaf Jan Schmidt, KDE Accessibility co-maintainer, open standards 
accessibility networker, Protestant theology student and webmaster of and

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