Details of the invitation to join the beta testing have been posted on the UIQ developer community:

The latest beta of the Carbide.c++ 1.3 IDE includes a UI designer for UIQ 3. The UI designer is a graphical tool in Carbide that makes it possible for developers to create a UIQ 3 application, or at least the foundation for one, by clicking and dragging commands, controls, editors, list boxes etc. to a design area. The tool generates all the necessary files for a UIQ 3 project (source code, header files, project files, resource files etc.) and places them in an appropriate folder structure. The generated source code is essentially a skeleton code in which the developer can add his/her own code to provide functionality.

As a beta tester you are encouraged to report all bugs you may find, from unclear warning messages to errors or sub-optimal generated code, as early as possible. Put "UIQ UI Designer" as part of the bug summary. To join the beta testing program, have access to the bug tracking system and download the latest beta of Carbide.c++ 1.3, you need to register at http://groups.google.com/group/carbidecpp-beta. The beta testing period ends on Sunday 2008-02-10.

Once you sign up to the Google-group, you will get an email notice that your subscription to the Google-group is approved, you can then download the latest release candidate. Note that if an error message appears immediately after signing up to the google group just disregard it and wait for the registration to be approved. Make sure you download build 19 (Carbide.c++_v1.3.0.019_rc1.zip) or later.