Current aspects of fused silica capillary column technology for gas chromatography are reviewed. Particular attention is focused on column deactivation and stationary phase properties. High temperature treatments with cyclic siloxanes or polysiloxanes are presently preferred for surface deactivation, and highly viscous polysiloxane polymers possess the best stationary phase properties. New crosslinkable polysiloxane stationary phases with different polarities and selectivities are constantly being produced, while new deactivation methods are much slower to develop. The chromatographic conditions used for column testing are critical for proper evaluation. Test conditions are often selected in order to give the impression of better than typical performance.