This paper presents the overall considerations and pedagogical approach which were at the basis of the development of an innovative web-based CALL application, Ellips (Electronic Language Learning Interactive Practising System). It describes the program's most salient features, illustrating in particular the technical challenges involved in the realization of this multilingual, server-hosted, database-supported language-learning application. Ellips, the product of a cooperative project between four Dutch universities, offers effective web-based support for language learning in Higher Education (HE) institutions. Ellips focuses particularly on grammar training, listening and pronunciation skills; although it can be accessed on its own, it has been created with integration with virtual learning environments (VLEs) like Blackboard and WebCT in mind. As a matter of fact, Ellips offers functionality lacking in these systems, which have not been specifically developed for language learning and offer more assessment than practising opportunities. Moreover, in Ellips all learning materials are coded with language-specific metadata (mainly based on descriptors derived from the Common European Framework), so that developers can easily find and reuse materials and so-called "semi-adaptivity" is allowed (students automatically receive more exercises on the topics which they have not yet mastered). Other important features of Ellips are full Unicode support, extensive feedback (for every item in an exercise and for the whole exercise), a student-tracking system, the use of (streaming) audio and video, and the possibility to record student input and store it in a portfolio.