Building using CMake
CMake generates build files for a variety of systems - you can choose whichever one you prefer, but the examples below are the most likely to work.
Building inside the source directory is strongly discouraged - create a build directory next to your source directory, and run Cmake from inside the build dir.
CMAKE_INSTALL_PREFIX specifies the location the compiled code will be installed to, but also adds library and header search paths. If you configure OpenSceneGraph, SimGear and FlightGear with the same value of CMAKE_INSTALL_PREFIX, most things will work automatically.
Linux / Unix
Install Boost, libpng, OpenAL, ALUT
Default Cmake target is regular make. Do 'cmake, make, make install' for OpenSceneGraph, then SimGear, then FlightGear
set CMAKE_BUILD_TYPE = Debug or Release as desired.
Install Boost, PLIB from Macports Install James' ALUT framework
Basically the same as above! Don't need to set CMAKE_BUILD_TYPE, can be done inside XCode
Windows MSVC 2010
Get Fred's latest 3rd party zip