Music processing in Linux: equal temperament, just intonation etc.

Can anyone point me in the direction of resources for music/sound processing in Linux? My specific target is to use my newly-acquired Raspberry PI as a demonstration tool for different tuning schemes, e.g. just intonation, or equal temperament. (If you don't know what these mean then trouble yourself no further!) I'd need some sort of keyboard input, probably, and some way of specifiying the tuning scheme details, and facilities for sounding chords and so on. My input source is a book called How Equal Temperament Ruined Harmony: And Why You Should Care by Ross Duffin, if anyone's come across this.
Is this a reasonable project, or am I just wasting my time, given that I'm starting pretty much from scratch?

Not sure what you are running on the rasberrypi but if Debian

Debian Multimedia Sound synthesis packages

Hazel and rubberman who are musicians here may weigh in better on what you are looking for.

Many thanks for this. It is indeed Debian (Wheezy). I'm also interested in general sound handling. Any dead-tree resources that it is worth my while looking at? I'm a bit old-fashioned (like to read in the bath, and so on ...)

Scala is a very good program for creating scales and TiMidity++ is good for playing music in different tunings. Both these programs support the MIDI tuning standard, which is much better to use than the pitch bend method.
You can use VMPK to play scales and chords on the PC keyboard, if you don't have a MIDI keyboard.

This is an interesting website about historical temperaments.

Thanks for this, well beyond the call of duty. Although it does of course mean that what I had planned is largely redundant:( ...
But it'll be good practice anyway :D ...