I have just downloaded and installed the libre open source (GPL) Varkon CAD for WinXP, and will be testing it for its possible use (at least [ease of use] for me :) in architecture, in as much as I can test it for this capacity, since my knowledge of CAD in architecture is limited, and my memory of more involved CAD has gotten rusty... (although that could change. :)
That said, the suggestion is warranted to those hereon, especially those who have a good knowledge of, and/or experience in, architecture (as well as a sense of adventure, some "hands-on, self-made" optimism for open source CAD, and some free time ;) to give it a try. It's a very recent release, which may suggest some healthy development activity.
The release for Windows has also been GPL'd! VARKON for UNIX and Windows are free software distributed in sourcecode under the GNU/LGPL license as published by the Free Software Foundation. The full conditions of the GNU/LGPL license is available at: http:/www.fsf.org.
Varkon used to cost $875 USD for a Windows license.
Clips from the manual: VARKON is ideally suited for all types of variational design. Wooden houses, tools for ballbearings, welded steel parts or electrical installations are some of the products currently designed in VARKON using this technique... VARKON has been available for more than 15 years and the number of users are steadily increasing with systems installed in many Europeean countries as well as the USA. Customers range from big companies like SAAB Aircraft to very small companies with only a few employees. There is also an increasing number of users all over the world running the free version of VARKON for UNIX and GNU/Linux. VARKON is a powerful geometric modeller. Basic 3D entities are points, lines, arcs, curves, surfaces, coordinate systems and transformations. Several representations of parametric curves are implemented including rational polynomial, analytical offset and curves on surfaces so called UV-curves. Surface representations include rational polynomial, lofted procedural, analytical offset and a faceted surface for approximations. Operations include intersects, closest point, silhouette, curvatures, transformation, trimming, export, import and approximation. Basic visualization as well as complex rendering based on OpenGL is included in all versions of the system.
Can it be? Finally, a libre, open source CAD program that is learnable, usable, does 3D, runs under Windows, and is good enough to do architecture?