Fontconfig is a library for configuring and customizing font access.

Fontconfig can:
* discover new fonts when installed automatically, removing a common
  source of configuration problems.
* perform font name substitution, so that appropriate alternative fonts
  can be selected if fonts are missing.
* identify the set of fonts required to completely cover a set of
  languages.
* have GUI configuration tools built as it uses an XML-based
  configuration file (though with autodiscovery, we believe this need is
  minimized).
* efficiently and quickly find the fonts you need among the set of fonts
  you have installed, even if you have installed thousands of fonts,
  while minimizing memory usage.
* be used in concert with the X Render Extension and FreeType to
  implement high quality, anti-aliased and subpixel rendered text on a
  display.

Fontconfig does not:
* render the fonts themselves (this is left to FreeType or other
  rendering mechanisms).
* depend on the X Window System in any fashion, so that printer only
  applications do not have such dependencies.

Homepage:
https://www.fontconfig.org/
