Pyspice is an easily extendable SPICE pre-processor written in Python to reduce simulation times with little loss in accuracy. It was inspired by John Sheahan's spicepp and developed as a modular and extensible method of pre-processing netlists. Primarily, it has been used to reduce netlists from the output of layout extraction tools. It combines parallel MOSFETs and capacitors, and optionally drops small capacitors. Planned improvements include a hierarchical namespace (e.g. .subckt/.ends and .alter blocks), more devices, and .include/.model support. Unlike other pre-processors, comments and blank lines are preserved in their relative positions. This keeps the output netlist readable for subsequent editing or processing.
To allow for identification, resistors are usually marked with colored bands. Often referred to as color codes, these markings are indicative of their resistance, tolerance, and temperature coefficient. gResistror is a great program that will help you translate resistor color codes into a readable value. All you have to do is watch the colors on the resistor and then enter them in the program. As you enter, you'll see that the resistor value is changing according to the selected color.
ibistools is a small set of command-line tools that aid a PCB designer working with IBIS models. It currently consists of a full IBIS v4.1 parser and an IBIS to SPICE translator. IBIS (I/O Buffer Information Specification) is a standard, human-readable, machine-readable format for publishing IC specifications.