There is an enormous number of software packages out there for doing Electronic Design Automation (EDA). More or less comprehensive listings can be found at Wikipedia, OpenCollector, OpenCircuits, EverythingPCB, Massmind, Terry Pinnell and ePanorama. We are looking into these to see whether we can build our efforts on top of them, and whether they can provide us with inspiration on how to do things.
The main services that EDA packages offer are schematic capturing, PCB layouting (sometimes with auto-routing), preparation for manufacturing and simulation. These services are often offered as separate modules wrapped in a software suite.


Open Source Suites

gEDA

gEDA is a suite of several tools (some of them independent) around EDA tasks. It has quite a long history and is extensively developed. The GUI however is quite cumbersome and outdated. Very good and up-to-date documentation and active community.
Language:GUI: GTK+  Platforms: Linux, Mac OS X  License: GPL
Potential: A potential base for Fritzing! We need to find out how we could program our own GUI on top of their EDA libraries since we do not want to go with their GTK/C. Interesting: gspiceui is an alternative UI for the SPICE package - maybe we can follow its model.

KiCad

KiCad is also a suite of tools, but more tightly integrated. It's much younger that gEDA, but nevertheless seems to cover the whole tool chain. The UI is very nice, and also has 3D view of the PCB. It is actively developed, has a well-designed code base. Documentation is rather thin.
Language: C++  GUI: wxWidgets  Platforms: Linux, Mac OS X, Windows  License: GPL
Potential: Another potential base! There is currently an initiative to create Python binding so that we could program a UI layer with wxPython (discussion). Some questions from us are discussed here.

OpenCircuitDesign

OCD is another suite of loosely connected EDA tools. The website looks out-dated, but the information is actually up-to-date and some of the tools are under active development. However, it does not seem to be widely used and is hardly documented.
Language: C, GUI: Tk, Platforms: Linux, Mac OS X, Windows, License: GPL
Potential: Not sure. The code might be good and it seems that the tools are even scriptable, but there's little life around this suite.

KTechLab

Another circuit design tool, specifically targeted at microcontroller circuits. It does not support PCB design, but features microcontroller simulation. It has a very nice UI, unfortunately only for Linux. Development is not very active, and documentation is poor.
Language: C++  GUI: KDE UI  Platforms: Linux  License: GPL
Potential: The parts for simulating a microcontroller might be interesting.


Open-Source Tools

These are independent tools that solve parts of the problem, and are interesting for inspiration for coding and designing the UI.

TinyCAD

A nice, complete editor for schematic capturing of circuits. Last update almost two years ago, but still an active user community. Unfortunately only for Windows.
Language: C++  GUI: MFC  Platforms: Windows  License: LGPL
Potential: Some implementation details might be interesting.

FreePCB

A PCB editor that is targeted at beginners and simpler PCB layouts. It seems to be quite popular and is actively developed, and also has a very nice user guide. Again, unfortunately it's only for Windows.
Language: C++  GUI: MFC  Platforms: Windows  License: GPL
Potential: The guide is helpful, and also the integrations/add-ons for the missing steps in the tool chain. There is for instance a tight integration with the free online auto-router FreeRoute.

Java Breadboard Simulator (Link 2)

A learning tool for simulating circuits plugged together on a virtual breadboard. The source code is not directly available, but might be on request. This one is interesting for its UI, which was inspired by Vulcan Trainer. Also has a good documentation.
Language: Java  GUI: Swing  Platforms: Linux, Mac OS X, Windows  License: ?
Potential: Similar UI idea, try it out!

EAGLE 3D

Provides high-quality 3D visualizations for EAGLE boards with POVRay. It uses the EAGLE scripting language ULP to export the board in POVRay-format.

Solve Elec

A rather simple, yet interesting tool to create and simulate circuits. Parts appear in a schematic world only, but there are other views for entering and evaluating electric formulas and even render some graphs.
Language: unknown GUI: unknown Platforms: Mac OS X, Windows License: Free, but closed source
Potential: Interesting for electrical rules checking and some UI solutions

Quite Universal Circuit Simulator - QUCS

Very powerful simulator (in alpha, though) which offers a lot of simulation and analysis tools. They use a very simplified GUI and draw circuits in schematics only. It's not targeting part-time tinkerers but rather electrical engineering experts. Compliance with various electric standards is a big issue on their roadmap. Project iniated at the TU Berlin.
Language: C++ GUI: QtPlatforms: Linux, Mac OS X, Windows  License: GPL
Potential: Could be a very hand extension of Fritzing's capabilities!


Commercial Suites

Innumerous EDA packages are available on the market, ranging from a few bucks to a few thousand. The large players are Altium (formerly Protel), Cadence OrCAD, Mentor, Synopsys and others. The ones listed here are chosen because they're interesting for various reasons.

EAGLE

Very popular among hobbyists, offers a limited Freeware version that is enough for most homebrewn PCBs (limited size and layers), and reasonably priced full versions.
Vendor: CadSoft  Platforms: Linux, Mac OS X, Windows  License: Free non-commercial version, Light/Std/Pro versions (50€-1500€)
Recommendation: A possible alternative base to the open-source ones. EAGLE has powerful scripting capabilities that could allow us to create an alternative UI. Otherwise, it would be great if we could stay compatible with EAGLE file formats.

CircuitWizard

A very nice low-cost solution targeted at education purposes. Interesting are the different views on a circuit (including breadboard-style) and the real-world-style analysis tools. Check out their tutorial video.
Vendor: New Wave Concepts  Platforms: Windows  License: Std/Pro/Edu versions (100€-200€)
Potential: A very good model of what we would like to achieve!

Abacom Electronics-Software

sPlan, Sprint-Layout, LochMaster, etc. are low-cost solutions for beginner/hobbyist. There are some nice ideas that could be interesting for us, for example the two-sided stripboard view (LochMaster), or the footprint wizard.
Vendor: Abacom  Platforms: Windows  License: Commercial (40€ each)
Potential: Some interesting ideas to learn from


Commercial Tools

VirtualBreadboard

A simple simulation tool for microcontroller circuits also based on a loose breadboard metaphor. It's possible to simulate the PIC or BasicStamp2 and offers a dev kit to program more components.
Platforms: Windows  License: Academic/Personal (15-30€)
Potential: Might be a model for simulation, if we want that.

VeeCAD

Not for PCB, but for stripboard design - and thus also interesting for prototyping when you want to start with a schematic diagram. I also like the graphics.
Platforms: Windows  License: Free, Commercial (20€)
Potential: Should be supported and mentioned by Fritzing

ExpressPCB

Offers free software with their PCB manufacturing service. Interesting because it is possible to get a quote and order from inside the software.
Platforms: Windows  License: Free
Potential: Similar service would be great: Upload the design to the website for feedback and join others to order together.


Your opinion

This is the result of a rather quick research of a person with little EDA experience. Please let us know you thoughts and join the discussion in the forums!