Agile Software Development (ASD) is a set of principles; Applied Agile Software Development (AASD) is one of the choices for making ASD work. AASD is a very tangible set of procedures to develop software in a mature and efficient way, based on the principles of ASD. AASD is comparable to XP and Scrum.

The main principles of Applied Agile Software Development's procedures are

• they should be very applicable; never propose a procedure that is "good in theory, but can't be used in practice".
• the procedures should mention all needed software tools (such as SubVersion, Eclipse, etc.), and its versions.
• there's strong emphasis to use FOSS tools, but that's not an imposition of the method. That is:

COTS tools are not forbidden. The most important goal is to have the method to be really applicable, useful and productive.

See more here.