Engeneers near free software desire a powerful CAD program to their GNU/Linux stations, and, when they read news like this in slashdot about little steps to open source by Autodesk they immediately think it’s possible in nearly future. Projects like qcad are too young, varkon is a good project, it’s used by SAAB Aircraft, but it hasn’t specific features to civil engeneering. By now, we must patiently wait.
About this, there is some confusion about file formats. I can read in Beowulf’s blog his post about Autodesk. Beowulf is civil engeneer and he’s Debian developer, so he can see both sides of problem. But I think he’s in a mistake: he’s interested in .dxf to be an open standard. Actually it is an open standard, but Autodesk includes privative extensions. As it’s explained in white papers of Open Design Alliance, .dxf is a poor format. ODA started its actions in order to achieve an open format compatible with .dwg
In 2003 ODA signed an important agreement with Bentley. The Bentley OpenDGN Initiative was born. So, everybody with his work in .dgn (it usually happen in road databases and maps in Spain and several GIS support it) they have complete control over it. Experts think dgn is better format than dwg, too (i.e. dgn supports serious units management).
Then I think the next step is a great free CAD project based in .dgn, not in .dxf nor .dwg