We present an approach to matching software practitioners' needs to software researchers' activities. It uses an accepted taxonomical software classification scheme as intermediary, in terms of which practitioners express needs, and researchers express activities. A decision support tool is used to combine these expressions of needs/activities, and to assist in studying the implications of that combined knowledge. This enables identification of fruitful connections between researchers and practitioners, of areas of common interest among researchers, and practitioners, and of "gaps": areas of unfulfilled needs or unmotivated research. We discuss the software engineering underpinning this approach, illustrating its utility by reporting on experiments with a real-world dataset gathered from researchers and practitioners. We also suggest that this same approach would be applicable to understanding the distribution of interests represented by presenters and attendees of a conference such as APSEC.