Innovation systems in developing countries differ largely from those in developed countries. A typical difference is that less developed countries have weaker institutional frameworks and low levels of interaction among the different actors in the innovation system. Scholars in innovation system research agree on the importance of understanding innovation systems in developing countries as systems in construction. Thus, while the most important organisations often exist, the critical linkages between e.g. user-producer and university- industry are still ill developed. The literature hitherto has been rather vague on how these systems can be built. We contribute to the literature by discussing the role of intermediate organisations in supporting different forms of interactive learning and linking relevant actors to each other in emerging innovation systems in developing countries, using data from Tanzania and El Salvador.