Spectre is a SPICE-class circuit simulator. It provides the basic SPICE analyses and component models. It also supports the Verilog-A modeling language. Spectre comes in enhanced versions that also support RF simulation (SpectreRF) and mixed-signal simulation (AMS Designer).
Spectre is currently a leading circuit simulator, competing with HSPICE and several others.
Spectre was developed at Cadence Design Systems by Ken Kundert and Jacob White.