What does the "w" mean after a shared library name?

Question

Some of my libraries have a "w" after the name. What does this signify?

For example I have the following shared libraries in /usr/local/lib:

libncurses.so
libncursesw.so
libmenu.so
libmenuw.so
libform.so
libformw.so

Answer 1

The “w” stands for “wide characters”, i.e. characters which occupy potentially more than one byte in memory; quoting the FAQ:

I chose to implement the wide-character support using a different library name, "ncursesw". Doing that allowed me to maintain compatibility with applications that used the existing "ncurses" library.