This AOSD 2009 workshop is the fourth workshop dedicated to the exploration of the area of domain-specific aspect languages, including language design, enabling technologies and composition issues.
The first edition was held at GPCE 2006 in Portland, USA, October 2006; the second edition was held at AOSD 2007 in Vancouver, Canada, March 2007; the third edition was held at AOSD 2008 in Brussels, Belgium, March 2008.
Proceedings are now available in the ACM Digital Library.