Abstract
This work describes a disk-resident database for Prolog which uses mechanisms similar to the ones used by the clausal database for recording and retrieving terms. It is intended to be used by applications requiring a flexibility greater than that provided by an interface to traditional database system. There is almost no restriction on the terms stored in the database and the retrieval mechanisms produces terms in the order they were recorded. To enhance the performance of the system, the database organization provides an access mechanism using hash-codes on ”key” arguments of the recorded term. The database also provides basic support for multi-user access. © Springer-Verlag Berlin Heidelberg 1989.

Abstract
Web interfaces are used nowadays for virtually every kind of computer application. The proliferation of web interfaces created the need to collect and analyze data on how users interact with them. Many web applications used for this purpose rely on what can be called a meta web interface. Meta web interfaces are used for different purposes but they share a set of common features: a web interface based on the subject interface with a second layer interface for collecting data, a central repository for persisting the collected data, and an API for retrieving aggregated data on user interaction. This paper describes Z-Web - a framework for developing meta web interfaces that provides these three features. To create a second layer in the meta web interface a Z-Web server is placed as a proxy between the web client and the subject web server and injects modifications while forwarding HTTP requests. These modifications are typically JavaScript libraries that collect and store data related to user interaction. The framework caches the pages it proxies and provides persistent storage for the collected data. An application interface (API) makes this data available to client application supported by Z-Web. This paper presents an overview of Z-Web, with the general architecture of a web application based on this framework, and describes the design and implementation issues of its main components. Two systems developed with Z-Web are also presented to evaluate the applicability of the framework and its overhead when compared with similar systems.

Abstract
The LMS plays a decisive role in most eLearning environments. Although they integrate many useful tools for managing eLearning activities, they must also be effectively integrated with other specialized systems typically found in an educational environment such as Repositories of Learning Objects or ePortfolio Systems. Both types of systems evolved separately but in recent years the trend is to combine them, allowing the LMS to benefit from using the ePortfolio assessment features. This paper details the most common strategies for integrating an ePortfolio system into an LMS: the data, the API and the tool integration strategies. It presents a comparative study of strategies based on the technical skills, degree of coupling, security features, batch integration, development effort, status and standardization. This study is validated through the integration of two of the most representative systems on each category - respectively Mahara and Moodle.

Abstract
Several Web-based on-line judges or on-line programming trainers have been developed in order to allow students to train their programming skills. However, their pedagogical functionalities in the learning of programming have not been clearly defined. EduJudge is a project which aims to integrate the "UVA On-line Judge", an existing on-line programming trainer with an important number of problems and users, into an effective educational environment consisting of the e-learning platform Moodie and the competitive learning tool QUESTOURnament. The result is the EduJudge system which allows teachers to apply different pedagogical approaches using a proven e-learning platform, makes problems easy to search through an effective search engine, and provides an automated evaluation of the solutions submitted to these problems. The final objective is to provide new learning strategies to motivate students and present programming as an easy and attractive challenge. EduJudge has been tried and tested in three algorithms and programming courses in three different Engineering degrees. The students' motivation and satisfaction levels were analysed alongside the effects of the EduJudge system on students' academic outcomes. Results indicate that both students and teachers found that among other multiple benefits the EduJudge system facilitates the learning process. Furthermore, the experiment also showed an improvement in students' academic outcomes. It must be noted that the students' level of satisfaction did not depend on their computer skills or their gender.

Abstract
We propose an interesting application of Constraint Logic Programming to automatic generation and explanation of mathematics exercises. A particular topic in mathematics is considered to investigate and illustrate the advantages of using the CLP paradigm. The goal is to develop software components that make the formulation and explanation of exercise's easier. We describe exercises by grammars which enables us to get specialized forms almost for free, by imposing further conditions through constraints. To define the grammars we concentrate on the solving procedures that are taught instead of trying to abstract an exercise template from a sample of similar exercises. Prototype programs indicate that Constraint Logic Programming frameworks may be adequate to implement such a tool. These languages have the right expressiveness to encode control on the system in an elegant and declarative way.

Abstract
AGILMAT is a web application designed to help students learn Mathematics, with focus on high-school algebra and calculus drills. A modular and extensible architecture and a wizard-based configuration interface decoupled from the system core are major design features of AGILMAT. The drill expressions are specified by grammars and constraints imposed by default profiles and user options, so that AGILMAT may support distinct learning levels and stages. The core system uses symbolic manipulation and automated reasoning to provide correct answers for the drills. The paper shows how AGILMAT may be used to create and customize drills automatically.