Editorial for the Special Issue on “Advances in Extended Reality for Smart Cities”

In the last few years, extended reality (XR) technologies, including virtual reality (VR), augmented reality (AR), and mixed reality (MR), have gradually expanded beyond their traditional entertainment domain and are now used in many other contexts. Today, XR applications play a role in education, healthcare, cultural heritage, industrial environments, and public services. At the same time, research on smart cities has turned its focus toward developing technologies with the potential to improve the interaction between citizens, digital services, and urban infrastructures.

Within this framework, XR is particularly interesting because it offers new ways to interact with information and physical spaces. Immersive technologies are no longer used exclusively to create visual experiences; they can also support communication, collaboration, training activities, public engagement, and access to urban services. For this reason, XR is attracting attention in smart city research, especially in areas in which the relationship between people and digital environments plays a central role.

Our Special Issue “Advances in Extended Reality for Smart Cities,” published in Future Internet, intended to collect recent studies exploring the use of immersive technologies in smart urban contexts. Its scope was not limited to technological aspects alone; contributions addressing accessibility, user experience, education, cultural heritage, and citizen participation were also welcome.

Following the review process, six papers were accepted for publication. The selected contributions include both research papers and systematic reviews and explore different perspectives related to XR applications in smart cities. The collected articles showcase how heterogeneous this research area has become, with topics ranging from artificial intelligence and sensing technologies to cultural experiences and urban well-being.

Some of the contributions focused on immersive experiences linked to urban and cultural contexts. Spyrou et al. [1] proposed a reference architecture aimed at integrating AI-driven virtual humans into metaverse applications for the GLAM sector (galleries, libraries, archives, and museums). Their work discusses how immersive and conversational systems may improve accessibility and user engagement in cultural heritage environments. In contrast, Rusho et al. [2] investigated the perceived value of information provided through augmented reality city experiences. Their study analyzed how users react to and evaluate urban information delivered through AR technologies.

Another group of papers addresses intelligent XR systems that integrate machine learning, robotics, sensors, and serious games. Ulrich et al. [3] presented SIGNIFY, a serious game designed for Italian Sign Language learning using gesture recognition and machine learning techniques. The contribution highlights the possible role of immersive technologies in supporting inclusive and accessible educational experiences. Fath et al. [4] proposed a framework for indoor infrastructure maintenance that combined networked sensors, robots, and augmented reality interfaces. Their approach aims to support maintenance activities in smart buildings by improving interaction between operators and digital systems.

The Special Issue also includes two systematic reviews dealing with broader perspectives on immersive technologies. Kostadimas et al. [5] reviewed studies combining VR, AI, and IoT technologies, discussing current trends and integration opportunities across different application domains, while Liang et al. [6] analyzed previous research comparing virtual reality experiences of urban green spaces with real-world exposure to nature, with a particular focus on mental well-being and urban sustainability.

Taken together, the submitted papers confirm the increasing interest in XR technologies within the context of smart city research. They also highlight how varied the possible application areas have become, ranging from cultural heritage and education to infrastructure maintenance and urban well-being. Several contributions also underline the importance of considering usability, accessibility, and user experience together with technological development.

The continuous evolution of technologies such as generative AI, spatial computing, adaptive interfaces, and digital twins is further expanding the range of possible XR applications in urban environments. For this reason, and considering the growing interest in this topic, a second edition of this Special Issue has been launched to continue collecting contributions related to Extended Reality for Smart Cities and related research areas.

The Guest Editors would like to thank all the authors who contributed to this Special Issue. We also sincerely thank the reviewers for their hard work during the evaluation process and for their helpful comments and suggestions. Their support was essential for maintaining the scientific quality of the published papers.