• Berkeley SPICE3f5
    The current version of Berkeley SPICE is SPICE3f5. It has all the basic functions of SPICE and is developed by the inventor of SPICE -- UC Berkeley.
    It is certainly free and you download it and find the manual here.
  • HSPICE
    As claimed by the majority of IC industry and academics in North American and Asia, HSPICE is the "gold standard" for high quality circuit simulation. It is a simulator with high a ccuracy as well as good measurement capabilities. HSPICE has its own GUI (graphic user int erface) for waveform viewing, but it is unfortunately a badly design interface. It runs on UNIX. Due to the fact that HSPICE is well recognized and trusted by the industry, simulation res ults of it is usually more persuasive. And it is certainly NOT free. For more information please see the company website.
  • Spectre
    Spectre is also a popular simulator developed by Cadence, which provides the famous well-integrated design front-to-back design kit.
    Spectre is also considered as simulator that gives high-accuracy results and provides a lo t of special waveform processing functions. It has fairly nice GUI but a lot of its functi on has to be done in GUI with its special data format. Spectre has its own syntax, but it can also read in standard SPICE syntax. While this limits its use in command line in a cer tain ways.
    Spectre also has a RF version SpectreRF for microwave IC design simulations. Spectre can only be purchased together with Cadence design kit, which is the standard desi gn tool for IC industry. Cadence design kit is capable to integrate the full design proces s from schematic entry, simulation to layout and extraction.
    The reason why industry prefers HSPICE is not clear to me.
  • PSPICE
    PSPICE is a very nice PC based SPICE version developed by Orcad, which is now part of Cadence. Its graphic interface is very straightforward and easy to use. So it is considered great for beginners. A lot of electronics textbooks for college students have added PSPICE as part of the contents.
    PSPICE uses standard SPICE syntax, with extra special functions.
    Besides IC simulation, the whole Orcad package also comes with PCB design tools to allow the full design and simulation of PCBs. The student version is available to download here:student 9.1.

  • Eldo
    Eldo is another simulator that comes with the whole design tool kit but it is available for purchase separately from Mentor Graphics. Though less popular for industry here in North America, Eldo is a well-recognized IC simulator with high accuracy in Europe.
    Its RF version EldoRF is one of the famous RF simulators. It comes with a GUI, but the interface is a bit hard to use.
    Eldo uses standard SPICE syntax, with extra special functions. It is HSPICE compatible.
  • ADS
    ADS is a PC based IC simulator developed by Agilent. As said in its name, it is another systematic design kit capable of the whole IC design process. It also has an RF version for microwave simulations.
    Developed by Agilent, which is the famous manufacture of high-quality measurement equipments, ADS has the advantage of modeling capability. Integrated with Agilent's equipment system, users can easily develop their own models for simulation.
  • XPSPICE
    XSPICE is developed by Georgia Institute of Technology. It is based on Berkeley SPICE3 with the extra capability to let users add new models using code-modeling techniques.
    Developed by the academics, it is free for the public. Details please see here.
  • NGSPICE
    With the goal of offering an open-source high-quality IC simulator, NGSPICE was developed by volunteers. It is modified from the basic Berkeley SPICE3 codes for a high accuracy, better convergence and more flexible functions.
    It is fairly easy to use, but more functions still need to be developed for this great open-source IC simulator!