Is compat5x really needed ?
Apparently, the libGL.so binary distributed with FreeBSD nVidia drivers is the only binary which needs compat5x in this package. When I install the ports' libGL after nvidia-driver (96xx or 71xx, I've got an integrated GeForce 4 MX) everything works fine without compat5x. It even solved a "black screen" problem I had with full-screen 3D apps when using 96xx drivers (I still have better perfs with 71xx though).
For example :
# portupgrade -f xorg-server
# portupgrade -f nvidia-driver
# portupgrade -f libGL
# pkg_delete -f compat5x\*
And after that, every 3D app works fine.
So, is there a reason for which this binary libGL is distributed with the FreeBSD nVidia driver ? Now that modular xorg is the only supported X server on FreeBSD, wouldn't it be better to remove the bundled libGL, depend on the graphics/libGL port, and remove compat5x dependency ?