Nuclear Magnetic Resonance (NMR) studies of 17 O in silicate glasses is beginning to provide new information on structure from an “anionic” viewpoint, which is an important complement to more traditional discussions of cation coordination and connectivities. A variety of techniques are discussed here, but the most important recent advances have used the new, two-dimensional, high resolution techniques of Dynamic Angle Spinning (DAS) and Triple Quantum Magic Angle Spinning (3QMAS), which have resolved and distinguished peaks for bridging oxygens linking Si, Al and B cations, as well as non-bridging oxygens. These approaches have provided some of the first quantitative constraints on the extent of ordering, both among network modifier cations and among network former cations.