  Extensibility mechanisms constitute a form of knowledge capture that is
essential for software re-use. The Data Intensive Cyber Environments (DICE)
group has collaborated with twenty-five science and engineering domains on the
application of the iRODS policy-based data management system. Based on these
collaborations, three types of extensibility mechanisms are sufficient to
capture the domain knowledge needed for interaction with domain resources:
computer actionable rules that control management policies; computer executable
micro-services that encapsulate operations or interaction protocols; and
middleware servers that apply standard operations at remote locations. These
mechanisms enable the creation of generic data management software that is
capable of implementing collections, data grids for sharing data, digital
libraries for publishing data, processing pipelines, and archives.
