Seeing as how the line drawing function in X doesn't do any anti-aliasing, the result would likely be very consistent across different environments even for fat lines. The problems to some extent are differences of opinion about how to make lines look pretty.
Sorry, i meant that it is buggy. Specifically the line\* drawing functions. I filled a 22x22 window with segmented lines and it blanked the window. A line across the leftmost pixels on the window (x=0) behaves differently then anywhere else. And such.
At least i think, as there is no hard spec on X11.
