ARIA is Garritan's 64-bit Sampler/Synthesis Engine, developed in collaboration with Plogue Art et Technologie Inc.
It is based on the SFZ 1.0 / SFZ 2.0 open file formats for instrument programming and the Scala open file format to define scales and temperaments.
The first software instrument in the ARIA engine was the Garritan Authorized Steinway Virtual Model D Piano Library, endorsed by and in cooperation with Steinway & Sons. Today, the ARIA Engine can be found in various software from Garritan, Plogue, AKAI, Sony, Microsoft and MakeMusic.
home page:
http://www.ariaengine.com/