The last decade has been of great significance for the development of slow light technology. Electromagnetically induced transparency (EIT), coherent population oscillation (CPO), stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS), soliton collision, and photonic crystal waveguides have been used to slow down the velocity of light. In this paper, some important theoretical and technical developments of slow light technology that occurred over the last decade are discussed. Novel technologies for slowing down the velocity of light and their primary applications are introduced in detail. In addition, the future developing trends of slow light and its potential applications, especially in optical fiber sensors, are also forecasted and proposed in this paper.