In this paper we report on one aspect of a qualitative study about an online wiki community, which was developed to build collaborative knowledge about poetry among a group of pre-service English teachers. Our paper explores pre-service teachers' experiences of writing in a digital medium and their perceptions of themselves as writers. We focus specifically on the processes of poetry writing (both collaborative and independent) undertaken in this digital medium by two groups of teachers, who were working in contrasting settings in the UK and Canada during their pre-service year. We investigate the affordances (Laurillard, Stratford, Lucklin, Plowman, & Taylor, 2000) that a multimodal, wiki environment offered these teachers for learning about poetry writing and question the impact that these affordances have had both on the teachers' collaborations and the poetry they wrote. In analysing the pre-service teachers' wiki writings we were interested to observe how they shaped themselves as writers and intervened in each other's work in progress within a digital third space. We also wanted to explore how the wiki had supported their professional learning about the teaching of poetry writing during their training year and the implications that this support could have for their own future classroom practice as teachers of writing.