In any case, my bottom line is that, even if you provide a portable geometry management mechanism, I ought to be able to just use actual XmForm, XmRowColumn etc widgets for the Motif version of an application. In particular, stylistic attributes (e.g. spacing, margins) which are set via resources need to be respected.
We could just add a platform-specific extension for the Motif backend. If somebody wants to implement a portable XmForm "clone", we could move it to the CGA proper. Proposal for Platform-Specific extensions: 1) Every backend may add additional functions to the CGA, which are only available for that backend. 2) Such platform-specific functions must be clearly marked as such. I suggest that we follow the example of OpenGL and mark extensions using a suffix to the name, e.g. mkXmForm_EXT, loadNibFile_EXT, etc. We could also use a platform-specific suffix, e.g. mkXmForm_MOTIF, loadNibFile_MAC etc. 3) A backend maintainer doesn't need to ask other backend maintainers for permission when adding extensions. Opinions? Cheers, Wolfgang