Purpose: The purpose of this paper is to describe educational MOOs--MUD, object-oriented (text-based, network-accessible virtual environments) and explore how teaching and learning in such a context impacts on students' inhibitions. Design/methodology/approach: Students enrolled in a course on the psychology of cyberspace interacted for 12 weeks in a MOO. The experience of being online, navigating around the space and interacting became the content of the course. Students kept a journal reflecting on their self-perception and presentation. This study is a qualitative analysis of these journals. Findings: Findings suggest that disinhibition in the MOO was common. Two types of disinhibition emerged: benign disinhibition (reduced shyness and increased confidence) and regressive disinhibition (dependent behaviour). Whereas benign disinhibition was frequently reported, regressive disinhibition was relatively rare and confined to new users. This second form of disinhibition was seen to arise from cognitive demands of the medium. Research limitations/implications: The implications of this study are that the text-based nature of MOOing, in particular its visual anonymity, appears to provide a context in which students feel able to "be themselves" and to interact with confidence. Limitations of the study include the self-reflexive nature of the course in which the data was collected. Caution is advised in generalizing different types of MOO courses. Practical implications: The research provides educators with potentially important information for facilitating confidence in students and helping to build learning communities. Originality/value: Few studies have examined the impact of MOOs on users' self-presentation and even fewer have explored the issue in an educational context. (Contains 1 table and 1 note.)