The development of in-house language learning materials has being going on for many decades. In the past, it was difficult for language teachers worldwide to share their in-house materials with other teachers, and so was having access to the materials developed by others. This often produced a feeling of isolation and, very frequently, provoked a duplication of efforts and a bigger investment of time. However, thanks to the Web 2.0 teachers and practitioners worldwide can communicate with each other and share experiences and materials. While this aspect of the so-called Social Web has being successfully exploded in the past few decades, especially in the case of online communities of teachers and practitioners worldwide, the possibilities of non-dedicated social and collaborative networks have not been so attentively looked. This paper describes the development of different language learning materials as well as some of the steps taken in order to get collaboration from users of two non-dedicated websites worldwide so as to increase the quality, authenticity and variety of those in-house language learning materials. The materials are part of the English online Course and Tester developed by the CAMILLE Research Group at the Universitat Politècnica de València (UPV), in Spain. Keywords: CALL; in-house materials; collaborative and social networks; software development; Web 2.0