WILGA Symposium on Photonics Applications and Web Engineering is a traditional multidisciplinary, multisession, meeting organized for more than two decades. WILGA gathers primarily young representatives of science, research and technology from such areas like optics, optical astronomy, photonics, optoelectronics, lasers, low energy and high energy photon science, lighting technology, but also physics, mechatronics, information technologies, material science and engineering, large research infrastructures for high energy physics and astronomical/space experiments, free electron lasers, tokamaks and stellarators, artificial satellites, etc. Topical sessions were organized around such particular and current research subjects like: bio-photonics, numerable development aspects of the Internet of Things, optical sensory networks, measurement systems for astronomy, photonics-electronics-mechatronics co-design and integration, large functional system design and maintenance, and other. Most of the participants are advanced PhD students just finishing their research theses, or just freshly promoted Ph.Ds. They are frequently accompanied by their eminent tutors, mentors, and work leaders from academia, industry, business or government. The XLII Wilga Summer 2018 Symposium was held 2-10 June 2019 in WUT Wilga Resort near Warsaw. Over 350 young researchers have gathered in Wilga during these days debating a number of research issues associated with the above mentioned areas and disciplines. The research results were presented either orally or in the posters. Over 300 presentations were shown to the participants, out of which over 220 relevant articles, and passing the reviewer criteria, are included in this volume of Proc. SPIE. The article is an introduction and overview of the 2018 WILGA Summer Symposium Proceedings. It emphasizes some key presentations and underlines new tendencies which may decide on the evolution of Wilga meetings in the near future. Wilga 2018 Symposium was split to the major large topical sessions, or conferences: Optics, Optoelectronics and Photonics, Computational and Artificial Intelligence, Biomedical Applications, Astronomical and High Energy Physics Experiments Applications, Material Research and Engineering, and Advanced Photonics and Electronics Applications in Research and Industry.