irrXML (you don't need to download it since it's included in the source of Aria)
(Please note that these instructions are for building with scons. You can also build with your favorite IDE/build system, but you'll then need to set up things yourself.)
First, download and install wxWidgets. I usually build static. Don't forget to enable OpenGL support.
Example terminal commands (read the instructions that come with wxWidgets for more info):
cd wxMac2.8.0 mkdir osx-build && cd osx-build ../configure --disable-shared --with-opengl make sudo make install
Make sure wx-config --libs points to the 2.8 libs when run from a terminal, otherwise you may need to copy wx-config to usr/bin
Then download and install scons. Just follow the instructions in the package, it's easy enough.
Then you need to build libjdkmidi - its source is included with Aria however it is built seperately.
cd /path/to/Aria/Src
cd libjdkmidi
make
cd ..
You can pass WXCONFIG=/path/to/wx-config to specify what wx-config to use when building.
All you need to do is type scons platform=mac or scons platform=linux (compiles but works only partially). This will do a debug build. For a release build, do scons platform=mac release=final Beta mode also exists. For more info about possible options, just type scons and instructions will be printed on the console.
Once you have the executable, you will need to package it as a mac OS X app bundle. The easiest way is to use the binary executable built by me that's included in the download. Go into Aria Maestosa.app/contents/MacOS, and replace what's there by the newly built executable (rename it so it has the same name). You must also copy the contents of Src/Resources into Aria Maestosa.app/contents/Resources.
In hope that it works! Otherwise you can always contact me