Status update for my haskell synth csound-expression. The main point is presence of many cool instruments. They are implemented in the package csound-catalog. All packages are compiled with GHC-7.10 So the hackage fails to build them and unfortunately docs a broken too. But you can look at the source code of the module Csound.Patch to now  the names of the instruments. The usage is pretty straightforward. It's described here:

https://github.com/spell-music/csound-expression/blob/master/tutorial/chapters/Patches.md

There is an mp3 file to listen to the instruments. http://ge.tt/1jNETqN2/v/0

The 4.8.3 is out! New features:

This is a very important release to me. It tries to solve the problem present in the most open source music-production libraries. It's often the pack of beautiful sounds/timbres is missing. User is presented with many audio primitives but no timbres are present to show the real power of the framework. This release solves this problem. See the friend package csound-catalog on Hackage. It defines 200+ beautiful instruments ready to be used.

The csound-expression defines a new type called Patch for description of an instrument with a chain of effects. It's good place to start the journey to the world of music production.

There are new functions for synchronized reaction on events. The triggering of events can be synchronized with given BPM.

The library is updated for GHC-7.10!

github repo: https://github.com/spell-music/csound-expression

hackage: http://hackage.haskell.org/package/csound-expression

Cheers!