--without-harfbuzz' to build without it. The HarfBuzz text shaping is
available via new font backend drivers 'xfthb' and 'ftcrhb' for Xft
and Cairo drawings, respectively, and via the 'harfbuzz' backend on
-MS-Windows.
+MS-Windows. The Harfbuzz text shaping is preferred to the previously
+supported ones, so the font backends that use older shaping engines
+(FLT on GNU and Unix systems and Uniscribe on MS-Windows) are not
+enabled by default; they can be enabled via the 'font-backend' frame
+parameter or via X resources.
** The new configure option '--with-json' adds support for JSON using
the Jansson library. It is on by default; use './configure