[Asterisk-Dev] Text to speech on Asterisk

[Joseph Riss]

On Sat, 2003-11-15 at 18:27, astdev at newww.com wrote:

[...]
> Asterisk. Regarding the GPL license, I'm sure we can work it out. I 
> believe that what I'm planing will abide by it. We write app_TTS for
> Asterisk that is full GPL, it is built with along with all the other
> apps and doesn't require any non-GPL headers. app_TTS uses a simple 
> protocol to communicate with any back-end TTS server that implements
> that protocol. I write a non-GPL glue code / server wrapper for the TTS
> engine, starting with Festival and Cepstral.
[..]

i was wondering why festival would need a "non-GPL glue code / server
wrapper for the TTS engine" ?
cepstral is commercial but isn't festival 'free for unrestricted use'
according to it's license?