The Max Planck Institute for Astronomy (MPIA) is happy to announce the upcoming meeting “Intergalactic Matters.” This weeklong workshop will take place June 16–20, 2014, at the MPIA in Heidelberg, Germany. As the dominant reservoir of baryons in the Universe, the intergalactic medium (IGM) plays a crucial role in the history and evolution of cosmic structure. The stars and black holes in the first galaxies galaxies emitted copious amounts of ionizing radiation, singly ionizing hydrogen and helium at z~10, and later doubly ionizing Helium at z~3, thus reheating and reionizing the cosmos. The IGM evolves into the clumpy cosmic web, which is the source of gas that cools and accretes onto galaxies powering star-formation, and a sink for the metal enriched material, energy, and radiation which galaxies eject. The complex interplay of these processes determines the physical state of gas in circumgalactic space, residing at the interface between galaxies and the cosmic web. Observations of absorption lines in quasar spectra from the present until redshift 7 provide a thermal and chemical record of the IGM, enable precision measurements of density fluctuations and the geometry of the early Universe, and provide invaluable insights into the physical processes shaping galaxy formation. In the past several years, advances in telescope instrumentation, the emergence of massive spectroscopic surveys, as well developments in theory and computation have deepened our understanding of the IGM and the circumgalactic medium (CGM). This workshop aims to bring together experts in the study of the IGM/CGM to discuss these recent developments.