In an increasingly fast-changing and diverse world, the role of socio-emotional skills has become more crucial. These skills are correlated with academic and professional achievement, healthier interactions, and greater well-being. Contrary to commonly believed, socio-emotional skills are not innate and can be taught and learned. Although there are established and accepted standards and curricula available for socio-emotional learning (SEL), they mainly focus on teacher-led instruction in a regular classroom setting, which brings the extra cost of the necessary support and teachers' training. One alternative is using technological resources to develop these skills. However, an open question is which technologies exist for SEL and what is the evidence of their impacts and benefits. This paper presents a systematic mapping to show how socio-emotional skills are being taught using technological resources. We analysed the results and suggested under-explored areas to develop socio-emotional skills with technology and computational artefacts.