The peer-reviewed electronic journal “Tribology Online” is dedicated to facilitating global exchange of up-to-date information among tribologists and researchers in relevant fields through rapid publication of high-quality papers on all aspects of tribology: science and technology of lubrication, friction, wear, lubricants, tribo-materials, tribo-systems, and so on. The journal is open access and fully supported by the Japanese Society of Tribologists; authors can publish with no publication fee, and readers can access the publication with no subscription fee.