+ It is not part of X/Open Curses.
+
+ Aside from <EM>ncurses</EM>, there are few implementations:
+
+ <STRONG>o</STRONG> systems based on SVr4 source code, e.g., Solaris.
+
+ <STRONG>o</STRONG> NetBSD curses.
+
+ A few functions in this implementation are extensions added for
+ <EM>ncurses</EM>, but not provided by other implementations, e.g.,