Research into the online informal learning of English has already shown it to be a widespread phenomenon involving a range of comprehension and production activities such as viewing original version television series, listening to music on demand and social networking with other English users. Dynamic systems theory provides a suitable framework within which to study informal learning because it emphasises the unique range of resources, strategies and relationships which contribute to non-linear language development for each learner. While research into the impact of these activities for language development has yielded some data regarding vocabulary gains and improvements in fluency and comprehension skills, the mechanisms at work in such language development have proved difficult to study because of the private nature of most online informal learning. In this study, an emic approach is adopted, involving a group of students experienced in second language acquisition research, who used blogs to report on their own online informal learning of English over a three-month period. Extensive examples from these blogs are used to build up a picture of the learning processes at work, within a framework suggested by the literature of complex dynamic systems. These results allow conclusions to be drawn regarding the way in which these processes are used by informal learners in different phases of real communicative tasks.