The Lncs Journal Transactions On Aspect-oriented Software Development Is Devoted To All Facets Of Aspect-oriented Software Development (aosd) Techniques In The Context Of All Phases Of The Software Life Cycle, From Requirements And Design To Implementation, Maintenance And Evolution. The Focus Of The Journal Is On Approaches For Systematic Identification, Modularization, Representation And Composition Of Crosscutting Concerns, I.e., The Aspects And Evaluation Of Such Approaches And Their Impact On Improving Quality Attributes Of Software Systems. This Volume, The 9th In The Transactions On Aspect-oriented Software Development Series, Contains Three Regular Submissions And Two Special Sections, Each Consisting Of Two Papers.