There are many CALL resources available today but often they need to be adapted for level or culture. CALL practitioners would like to reuse currently existing material rather than reinvent the wheel, but often this is not possible. Thus, they end up building CALL material, both language content and software, from scratch. This is inefficient in terms of CALL practitioners’ time and as Felix (1999) points out, there is no point ‘doing badly’ what has already been done well. Why can’t we reuse what already exists? Often the language content is hard-wired in the software and cannot be modified or the CALL material comes as an executable which is hard or impossible to change. Authoring tools can provide a degree of flexibility, but often focus on particular parts of the language learning process (e.g. interactive exercises) and the associated language content cannot, in general, easily be exported into other formats and presentation software. One solution to this problem is provided by XML technologies. They provide a strict separation between data and processing. Thus, three types of reuse are possible: reuse of the data processing engine (i.e. the XSL processing files), reuse of the language content structure (i.e. the XML data files) and reuse the linguistic resources (i.e. the language content). In this paper, an example is given of a CALL template that has been developed using XML technologies. The template provides a structure into which the language content can be slotted and a processing engine to act upon the data to create CALL material. The template was developed for the production of CALL materials for Endangered Languages (ELs), but could be used for MCTLs (Most Commonly Taught Languages) and LCTLs (Less Commonly Taught Languages) also. It has been used to develop a language learning course for Nawat (a language of El Salvador), Akan (a Ghanaian language) and Irish, demonstrating the reusability of the language content structure as well as proving the reusability of the processing engine provided by the template. A further reusable feature is the ability to create courseware in different media (Internet, CD and print) from the same source language content.