This is a Arduino Library for the Analog Devices AD57X4 family of precision DACs. More details can be found here: https://www.laserlance.com/projects/arduino-dac-library-and-shield/
1.0.3 is the mature and stable branch, but it does not have daisy chain support. It will not be maintained further.
Version 2.0b will have daisy chain support, but is not backwards compatible with 1.0.3. The main branch will be maintained.