tclmpds is a pure-Tcl package for communicating with MPD. The name stands for "Tcl MPD Socket" (since it's intended to be low-level).
Now it's in its very infancy: the proper API is being developed and now the package is only able to reliably connect, talk to MPD, parse errors and perform a few commands.
After the package is complete, the next step will be to create a pure-Tcl/Tk GUI frontend on top of tclmpds -- putting up another cross-platform MPD client.
The possibility to create a (Tcl-scriptable) command-line client on top of tclpmds also sounds interesting.
This will probably require implementation of a higher-level package for client-side playlist manipulations, etc.
This package is being developed by Konstantin Khomoutov . Feel free to contact me if you want to participate. But note that the internals of the library haven't settled down yet.
The package's sources are kindly hosted by musicpd.org Subversion repository at  .