This is the Alan SDK for MacOSX which consists of the compiler, an interpreter, the manual and some examples. The MacOSX version are command line based, suitable both for Terminal command based work and for use with the AlanIDE, which is the recommended tool for authoring and compiling.
This is the Alan SDK for Linux which consists of the compiler, an interpreter, the manual and some examples. This is suitable for command line based work and for use with the AlanIDE.
The Alan SDK for Windows consists of the compiler, an interpreter, the manual and some examples. This is the command line version which you need if you are working from a command window or the AlanIDE.
The Alan SDK for Windows consists of the compiler, an interpreter, the manual and some examples. This is the GUI version which you need if you are working from the Windows GUI/Explorer view.
If you want to use the AlanIDE you need the command line version.