I mailed Dave Phillips about PenguinSound, and he offered to list it on his Linux Sound Applications list. He also recommended subscribing to the Linux Audio Development Mailing list. I took a look at ardour by Paul Barton-Davis. The screenshots look impressive but I've yet to try it out.
I've been considering refactoring my filter, and generator classes to make them much more flexible. The current setup is not sufficient to support LADSPA plugins.
Its getting hot in Sydney.