I've started to transition the LibreCAD icons to Tango. The existing LibreCAD main toolbar is on the left, SodaCAD on the right.
There is still a lot of work to be done. Icons which do not have a Tango equivalent will need to be created to Tango specifications.
The things I ask myself as I work through this:
1. Does the visual representation of the icon convey proper meaning?
2. Does the replacement icon fit within the visual theme?
3. Does the replacement icon improve the overall look?
The hope is that the Tango and Tango-style icons will conform with other open source graphics apps like Inkscape, Gimp, and Scribus and convey equivalent meaning and understanding among users.
I've updated the code base to reflect these changes but they are in no wise the final say. I welcome feedback.