Colin is a structural analysis application with a lightweight Interface.
Colin is part of the Qt Ambassador Program.
Thanks to Jeff Wurth, some videos with explanations (in german) are avaialable here and here.
For more information, feedback and contact take a look at the bugtracker.
It is now available for Linux from deb.Clazzes.org, see *-colin-1.list there, as well as Windows (32 and 64 bit, from our Download area).
You can find the source code in our SVN Repository at http://svn.clazzes.org/svn/colin/trunk/colin.
The according Jira-Project is COLIN.