Captain
The Captain Russian voice.

Festival
This gives NVDA support for the Festival synth.

JPTalk
This is a robotic sounding Japanese synth.

JTalk
Japanese speech engine for NVDA, based on Open JTalk, MeCab and MMDAgent.

Newfon
The russian newfon speech synth.

Protalker
Driver for the protalker synth.

RH Voice
The RH russian voice.

SAM
SAM, Formally Synthesizer access manager, is a utility that comes with Supernova Access Suite in which you can run Orpheus. Just install Sam, Orpheus and this add-on and you can use Orpheus.

smpsoft
Driver for the smp synth.

svox Pico
Svox pico synth.