I’ve built a Linux version of phi-T Effect S. It works perfect with Ubuntu Studio 11.10, but I haven’t checked other Linux distributions yet. The supported audio driver is ALSA (the Advanced Linux Sound Architecture), which also provides MIDI functionality for phi-T Control. JACK audio is currently not supported, but this would be a cool feature, especially for Ubuntu Studio.
With my Native Instruments audio interface the latency is lower than 10 ms, hence not hearable.
To download the executable, see the project’s page in the tab above.