Open-plan offices are common in today's organisations. These types of workplaces require people to share a common space, where violation of (implicitly or explicitly stated) social norms can cause instances of incivility. If nothing is done to avoid these situations, bad feeling can lead to diminished productivity and cooperation, and, in the long-term, to more serious problems, such as conflict and aggression. A critical review of literature shows the effects of workplace incivility and the need for an internal reparation mechanism. Inspired by convergence of pervasive, adaptive and affective computing, we have designed and developed a self-regulatory platform for successful collective action, based on participatory adaptation and fair information practises, which we called MACS. MACS addresses the problem of incivility and aims at improving the Quality of Experience in shared workplaces. This thesis presents all studies that led to the development of MACS. Through the analysis of an online questionnaire we gathered information about incivility in shared workplaces, how people deal with those situations, and awareness about uncivil self-behaviours. We concluded the main issue while sharing a workplace is noise, and most people will try to change their own behaviour, rather than confronting the person being uncivil. MACS's avatar-based interface was developed with the purpose of heightening self-awareness and cueing the appropriate social norms, while providing a good User Experience (UX). Avatars created to people's image, rather than photos, were used, to keep MACS's tone light and relatively unintrusive, while still creating self-awareness. MACS's final version went through UX testing, where 6 people were filmed while performing tasks in MACS. The intended work-flow and user interfaces to support the smooth passage of the work-flow have been validated by the UX user testing. There is some preliminary evidence suggesting apology will elicit empathic responses in MACS. Finally, this thesis proposes guidelines for workplace design, which are founded on participatory creation and change of social norms, and ways to make sure they are enforced. In this sense, MACS can also be seen as a prototypical example of a socio-technical system being used as platform for successful collective action.