The paper elaborates on the assumption that in modern organisations collaborative learning is an enacted capability that is more about "acting" and co-engaging in shared practices. In such settings, virtual learning can be conceived as an emergent knowledge process with no pre-determined outcomes that occupies multiple online and offline constituencies. Then, retaining and visualizing the history of co-engagement in practice becomes a pre-requisite for effective e-learning environments. Using two case studies exploring the social production of radically different information-based products, namely networked music performances and vacation packages, the present work frames virtual learning in the traces online ensembles leave as their members co-engage (both online and offline) in socially constituted activities. The analysis leads to several findings, with most prominent the following: (a) "Knowing" is accomplished through recurrent co-engagement in a designated practice, (b) Learning in online settings emerges through the intertwining of online and offline activities, and (c) Artefacts of practice need to embody critical design qualities, if they are to serve learning as "knowing" in practice. (Contains 1 table and 8 figures.)