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.
Alliance CAD System is a set of EDA tools and portable cell libraries for VLSI design. It covers a wide range of the standard design flow (from VHDL up to layout). It includes a VHDL simulator, RTL synthesis tools, place and route tools, netlist extractor, DRC, and a layout editor.
PEP is a modeling and verification framework for parallel systems. It provides a large number of different modelling languages (e.g. SDL, B(PN)^2, Petri nets, Process algebras and Finite Automata), and verification techniques (e.g. reachability and temporal logic model checking). Due to its Tcl/Tk-based GUI, PEP is easily extensible to other analysis or specification tools. The framework offers fully integrated simulation and debugging features on all levels.
nMicrocoder is an ncurses EDA tool to write microcode. Basically, it is a stripped down spreadsheet program that lets you fill a table with "0", "1", and "-", and gives you compile-ready verilog code in return. It was written as an alternative to full spreadsheet programs. It is known to run on Linux, IRIX, and Solaris, unless ncurses 5.3 is installed.
JCCad is a project to develop a 2D/3D CAD program that can be used to create technical drawings. One of the main goals of this project is to include a plugin system to allow usuaries to make new commands. In this way it will be easy to use the program for any particular task. JCCad provides an easy interface with a command line.
libmls is a library that can be used to measure the frequency response of a loudspeaker or a room using your computer and an ordinary soundcard. It can perform both MLS (Maximum Length Sequence) and Sinus sweep measurements. It supports ALSA, OSS, and the sound system used in Windows.