X-lites network builds international collaboration at the frontiers of laser science and applications.The invention of the laser in 1960 enabled a wide range of scientific and technological advances, from communications to surgery to facial recognition to analysis of Martian soil. Laser science and technologies continue to advance, and a new generation of lasers are accessing frontiers of laser-matter interactions at the highest intensities, the fastest times, and the shortest distances. The Extreme Light in Intensity, Time, and Space (X-lites) network builds on these technological advances to organize and support scientists around the world as they research and apply this extreme light. X-lites is a new global network of networks that unites the work of scientists across disciplines and geographic borders to support the next generation of scientific advances, scientific workforce training, and skills development. X-lites accelerates discovery and invention through its support of team building, knowledge sharing, and education across disciplinary and national borders.<br/> <br/>X-lites applies the Science of Team Science (SciTS) to build on existing networks of researchers developing and applying extreme light. X-lites exploits prior US and European investments in research facilities that provide access to cutting edge extreme light capabilities. The X-lites network foundation is a coupled, two-layer network concept that has proven to be effective in forming impactful networks. One networked layer links 10 user facilities/collaborations, and the second layer links these facility's users. Users are a diverse community of researchers taking advantage of infrastructure investments to explore questions in physics, chemistry, biology, materials, and more. X-lites hosts virtual seminars and workshops, conducts courses on effective team science for early career researchers, funds the exchange of early career staff between facilities, and brings together researchers across disciplinary boundaries to explore scientific frontiers. These activities intentionally engage early career and diverse researchers (i.e., diverse demographics, scientific specialties, and geographic locations) who are the future of these fields and who will drive X-lites and extreme light science, technologies, and applications forward.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.