This is not an April Fool's joke. KMid is running in Mac OSX, native:
I've developed KMid's Mac native support using Fink, that includes KDE SC 4.4.1
By the way, there are fresh news at Fink web site: "Effective 1 May 2010, we are going to cease work on our Mac efforts, and switch to development for the iPad, iPhone...". Oh, wait! today is April 1st...
Now seriously. You need: Xcode 3.1.4, that provides GCC 4.2
And some dependencies from Fink: kdelibs4-mac-dev, kde4-buildenv, cmake. These packages require some other dependencies.
Recommended: bundle-kde4-mac. This set is very large, and includes everything for a complete KDE environment.
KMid doesn't use Phonon. The native Mac OSX backend uses CoreMIDI and CoreAudio, and the Apple DLS soft synth enabled by default. Everything is included in OSX. Receipt:
1. Get the sources from the repository:
$ svn co svn://anonsvn.kde.org/home/kde/trunk/extragear/multimedia/kmid/
2. Prepare the build environment:
$ export KDE4_TYPE=mac
$ source /sw/sbin/kde4-buildenv.sh
3. Configure, compile, install:
$ cd kmid
$ mkdir build
$ cd build
$ cmake .. -DCMAKE_INSTALL_PREFIX=/sw/opt/kde4/mac -DBUNDLE_INSTALL_DIR=/sw/opt/kde4/mac/bin
$ sudo make install