Sorry for not providing specific description about what I want.
I asked the question in broad and obscure scope because I don't know exactly how to do it systematically and reasonablly and I thought maybe people know Linux better can give me some insight.
I have removed some files in /usr/lib and put my ported libs in /usr/local/lib. Here is the list of libs removed from /usr/lib. X-related libs are not touched. I put newer GTK+ libs in /usr/local/lib.
Code:
glib-2.0
gtk-2.0
pango
libatk-1.0.so.0
libatk-1.0.so.0.1011.0
libgdk_pixbuf-2.0.so.0
libgdk_pixbuf-2.0.so.0.600.7
libgdk_pixbuf_xlib-2.0.so.0
libgdk_pixbuf_xlib-2.0.so.0.600.7
libgdk-x11-2.0.so.0
libgdk-x11-2.0.so.0.600.7
libglib-2.0.so.0
libglib-2.0.so.0.600.6
libgmodule-2.0.so.0
libgmodule-2.0.so.0.600.6
libgobject-2.0.so.0
libgobject-2.0.so.0.600.6
libgthread-2.0.so.0
libgthread-2.0.so.0.600.6
libgtk-x11-2.0.so.0
libgtk-x11-2.0.so.0.600.7
libpango-1.0.so.0
libpango-1.0.so.0.800.1
libpangoft2-1.0.so.0
libpangoft2-1.0.so.0.800.1
libpangox-1.0.so.0
libpangox-1.0.so.0.800.1
libpangoxft-1.0.so.0
libpangoxft-1.0.so.0.800.1
Actually, I don't know which lib is replacable and which is not. So I did this by trial and error. I will try to only replace GTK+ related libs (including glib, pango, cairo,...) and leave X-related lib untoched. Thanx for your advice.