The Gala Framework: Version Support in Web Based Open Hypermedia

The GAIA framework prototype, described herein, explores the possibilities and problems that arise when combining versioning and open hypermedia paradigms. It will be argued that it by adding versioning as a separate service in the hypermedia architecture – is possible to build consistent versioning of both documents and hyperstructure. This approach eases some of the problems inherent in separating versioning of documents and structure and even allows versioning to be added to domains that would otherwise be unversioned. A brief introduction is given to research results in the hypermedia versioning field and GAIA is compared with previous attempts at defining hypermedia versioning frameworks. GAIA is capable of multi-level versioning and versioning of structures and supports freezing mechanisms for both documents and hyperstructure. The experiences from GAIA provide an input to new reference architectures for future versioned hypermedia frameworks.