Introducing Pergamos: A fedora-based DL system utilizing digital object prototypes

This demonstration provides a "hands on" experience to the "internals" of Pergamos, the University of Athens DL System. Pergamos provides uniform high level DL services, such as collection management, web based cataloguing, browsing, batch ingestion and automatic content conversions that adapt to the underlying digital object type-specific specialities through the use of Digital Object Prototypes (DOPs). The demonstration points out the ability of DOPs to effectively model the heterogeneous and complex material of Pergamos. Special focus is given on the inexpensiveness of adding new collections and digital object types, highlighting how DOPs eliminate the need for custom implementation. © Springer-Verlag Berlin Heidelberg 2006

A Software Development Metaphor for Developing Semi-dynamic Web Sites through Declarative Specifications

Traditionally, the realization of Web sites involves either static content developed using web authoring tools or dynamic content delivered by a database driven frontend, where the structured content is organized in a relational schema and dynamically generated on the fly. The limitations of statically-authored web pages are easy to discern and for a number of applications, the use of a database introduces a level of additional complexity that makes the choice a part of the problem space rather than the solution space. Based on the distributed software development approach, we present a suitable for managing middle-sized semi-dynamic web sites

Safely Composable Type-Specific Languages

Abstract. Programming languages often include specialized syntax for com-mon datatypes (e.g. lists) and some also build in support for specific special-ized datatypes (e.g. regular expressions), but user-defined types must use general-purpose syntax. Frustration with this causes developers to use strings, rather than structured data, with alarming frequency, leading to correctness, performance, security, and usability issues. Allowing library providers to modularly extend a language with new syntax could help address these issues. Unfortunately, prior mechanisms either limit expressiveness or are not safely composable: individ-ually unambiguous extensions can still cause ambiguities when used together. We introduce type-specific languages (TSLs): logic associated with a type that determines how the bodies of generic literals, able to contain arbitrary syntax, are parsed and elaborated, hygienically. The TSL for a type is invoked only when a literal appears where a term of that type is expected, guaranteeing non-interference. We give evidence supporting the applicability of this approach and formally specify it with a bidirectionally typed elaboration semantics for the Wyvern programming language