Behaviour guideline
Although GNOME HIG nicely specifies, how GNOME application should look, its says nothing about how application should behave. Its strange that our usability guys dont take such an important thing into account. Even small difference in program execution affects user satisfaction. For example, Open dialog saves location in one applications but makes me browse to the same directory every time in another. The main problem we are talking in that section is that programs should behave consistently, not only look consistently.
And some consequences.
Its impossible to get consistent behaviour without sharing codebase. One can make application written in Qt or with Mozilla suite look like Gtk application, but user easily see the difference way such applications do things. Once you open settings dialog, mirage of consistensy dissapear. HIG should not be recomendations everyone is trying to follow, but a documentation to hardcoded rules, that anyone using library is automatically following.
Integration with other toolkits doesnt have any sense, as supporting software on different platform. If application uses another codebase it will behave differently. Take, for example, gecko or gtk-mozembedd applications. They all have problems with keyboard focus and accessibility. Its impossible to make them work like GNOME user expected. Even if youll get them look similar, its impossible to maintain such consistensy every time something changes in gtk.
