ELocutor is free, open source software downloadable from http://holisticit.com/eLocutor/elocutorv3.htm. A discussion list is located at http://groups.yahoo.com/group/radiophony.
Part of the download is the entire source code. I might warn you, though, that it bears some resemblance to a bowl of spaghetti, for which I bear full responsibility. I hadn't programmed for more than 10 years when I started this project, so my skills were outdated and rusty. I did not have a design, only a few hints now and then on the direction in which it should evolve. The code grew with my understanding of the problem, and the results show it. Very simple programming techniques have been used, as is obvious from the code shown in this chapter.