TkGate is an event-driven digital circuit simulator with a TCL/Tk-based graphical editor. It supports a wide range of primitive circuit elements and user-defined modules for hierarchical design. The distribution comes with a number of tutorial and example circuits which can be loaded through the "Help" menu, and the example circuits include a simple CPU, programmed to run the Animals game. TkGate has multi-lingual support for English, Japanese, French, German, Spanish, Welsh, and Catalan.
SpiProg is a programmer for SPI (Serial Peripheral Interconnect) compatible EEPROMs used in many modern small electronic devices such as cellular phones. The package contains building instructions for a very simple parallel port adaptor and source code of the programming software. It has a small built-in command line driven hex editor and supports devices like Xicor X25640 and Atmel AT25080.
DiaCanvas is a generalized version of the drawing canvas used by DIA. It extends some features used by DIA and adds new ones, while preserving as many of the original features as possible. This project is no longer actively maintained. It is suggested that you try DiaCanvas2 instead.
XCircuit is a UNIX/X11 program for drawing publishable-quality electrical circuit schematic diagrams and related figures, and producing circuit netlists through schematic capture. XCircuit regards circuits as inherently hierarchical, and writes both hierarchical PostScript output and hierarchical SPICE netlists. Circuit components are saved in and retrieved from libraries which are fully editable. XCircuit does not separate artistic expression from circuit drawing; it maintains flexiblity in style without compromising the power of schematic capture.
BitGen accepts text strings of 1's, 0's and hex digits and converts them to equivalent "pwl" voltage sources for inclusion in netlists for circuit simulation (with SPICE or Spectre, for example). Periodic waveforms (eg, clocks) can be exported as "pulse" voltage sources. Parameters such as rise time, fall time, pulse width and duty cycle can be set on a waveform-by-waveform basis. BitGen is written in Perl with the Perl/Tk toolkit and has an easy-to-use graphical interface.
The Eagle EDA software is composed of tightly integrated modules for PCB design, including Schematic Capture, Board Layout, and Autorouter. There is a free full-function (only board size limited) non-commercial license available for hobby and educational use as well. Windows, DOS, and of course, Linux versions are available.
VIPEC is an network analyser for electrical networks. It takes a description of an electrical network, and performs a simulation of the circuit response in the frequency domain. Output is in the form of 2-port parameters, and can be plotted on a grid and in Smithchart format. VIPEC supports various lumped circuit elements, as well as elements like transmission lines and 2-port data files.