WormBase is pleased to introduce a new chromosome-based assembly of C. briggsae (version CB3) on the Genome Browser. This assembly was generated by combining genetic map data with updated information on the physical map. The original assembly of C. briggsae referenced in Stein et al., 2003 (cb25.agp8) is now archived, available by selecting C. briggsae cb25.agp8 release from the Genome Browser’s “Data Source” menu. Assembly provided by LaDeana Hillier; Genome Browser view by Sheldon McKay.