Charles Williams recently released a 'beta'version of MacSpice that is carbonized. MacSpice 3f5R6 is the latest version. This has a completely rewritteninterface and uses the Carbon libraries to run on Classic MacOS8.6 and later, and as a native Aqua application on OS X.
MI-SUGAR isa native Mac OS X application for analog circuit simulation. MI-SUGARwraps around the free simulation tools SPICE and Gnucap and actsas a user-friendly interface for circuit editing and analysistasks. It now features a schematic entry tool for graphical circuitdesign. MI-SUGAR is shareware and is mainly intended forstudents and hobbyists. You can create analog circuits using theschematic entry tool or the netlist editor, then run the simulationand analyse the results in the graph plotter. You can even exportthe results to Matlab® or Mathematica® file formats. Theapplication can be downloaded for free but the full feature setis available only after entering a license key, which costs only$15.
TclSpiceis an improved version of Berkeley Spice designed to be used withthe Tcl/Tk scripting language. The project is open-source (BSDlicense) and based upon the NG-Spice source code base with manyimprovements. This version supports the latest short channel spicemodels used by industry. Spice is typically used for transistorlevel simulations where you really need to analyze timing or someanalog function.
SpiceX is a Mac OS-X port of the SPICE 3F4 engine and is available from Idea Studios Ltd. Click on the "Special Projects" link to accessthe download link. Example files are included with the distribution.
LTSpice IV is a high performance SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators. Our enhancements to SPICE have made simulating switching regulators extremely fast compared to normal SPICE simulators, allowing the user to view waveforms for most switching regulators in just a few minutes. Included in this download are LTspice IV, Macro Models for 80% of Linear Technology's switching regulators, over 200 op amp models, as well as resistors, transistors and MOSFET models.