The emergence of Web as a ubiquitous platform for innovations has laid the foundation for the rapid growth of the Internet. Side-by-side, the use of mobile and wireless devices such as PDAs, laptops, and cell phones for accessing the Internet has paved the ways for related technologies to flourish through recent developments. However, development of these technologies and systems adds complexity due to the performance, fault tolerance, and availability requirements. These issues are required to be explored for the effective design and implementation of high-performance modern computing systems.In this special issue, we are delighted to present ten technical papers on resilient, highly available, and fault-tolerant Internet and distributed systems, with a particular focus on the practical experiences with the design and implementation of related technologies as well as their theoretical perspectives. These papers were selected out of 80 submissions from 17 countries in the 6th International Conference on Internet and Distributed Computing Systems (IDCS 2013). The selection has been very rigorous, and only the best papers in the conference were selected.Performance and dependability evaluation plays a key role in the design of a broad range of systems, especially when strict requirements need to be met. In the first paper, 'Variable Operating Conditions in Distributed Systems: Modeling and Evaluation' [1], Longo et al. present an analytical method that allows the study of a class of systems where different operating conditions alternate changing the stochastic behavior of the system components but still preserving the continuity of the performance and dependability quantities to investigate.In the second paper, 'Supporting Personal Security Using Participatory Sensing' [2], Carreno et al. propose a mobile collaborative application, named Personal Guardian, which used by civilians while walking in urban areas. The application is focused on crime prevention, and it implements participatory sensing to help people be aware of the risks that appear to exist in a certain place. This is an interesting application on information feeding process and the unattended delivery of awareness information about personal security.In the third paper, 'Self-healing Wireless Sensor Networks' [3], A. Miyaji and K. Omote propose three self-healing schemes to provide availability in wireless sensor networks. This is very important for long-term use of wireless sensor networks. These self-healing schemes are effective and efficient according to the evaluations done by the authors.Smooth data streaming in wireless sensor networks is a challenging problem. In the fourth paper, 'A Slot Demand based Path Reservation Approach for the Timely and Reliable Delivery of Bursty Traffic in WSNs' [4], P. V. Vinh and H. Oh propose an efficient approach to deliver bursty data reliably by reserving time slots to transmit the required packets on all the paths from the selected multimedia nodes to the server. The nodes that are not on the selected paths ar...