Mark Lucovsky writes:
As I look back on HailStorm, and try to distill it into some of its core concepts, I come up with the following list:
* Network Centric, Extensible Data Model, for Everyday Data
* Data Decoupled from Applications
* Anytime, Anyplace, and from Any Device Access
* Identity Centric Data Access
HailStorm was based on an XML data model. The system defined several core data types (calendar events, address book entries, bookmarks, profiles, etc.). Each core type had a set of required elements and attributes, and allowed for arbitrary extensions in both the element and attribute dimension, as long as those extensions are defined within a unique XML namespace. HailStorm had the notion of an “address” type which defined a set of base properties associated with an address. Anyone could easily extend an address by including arbitrary, well formed XML from an arbitrary namespace. The data model was simple to use, simple to extend, and simple to process. There was no need to buy proprietary tools to crack, parse, manipulate, re-transmit, or re-purpose any type.
Looking at HailStorm through this facet, there are clear similarities between it, and RSS 2.0 and Atom. These two core systems are very powerful. Their ease of use, their simple extensibility, their inherent network centricity have unleashed many clever and useful applications.