# External libraries

External library GD (used by PNG/JPEG/GIF/sixelgd terminals, pixmap): Versions of libgd through 2.0.33 had various bugs in mapping the characters of Adobe's Symbol font. Dot-dash patterns are not supported for these terminals.

External library PDFlib (used by PDF terminal, but not by pdfcairo): Gnuplot can be linked against libpdf versions 4, 5, or 6. However, these versions differ in their handling of piped I/O. Therefore gnuplot scripts using piped output to PDF may work only for some versions of PDFlib.

Internationalization (locale settings): Gnuplot uses the C runtime library routine setlocale() to control locale-specific formatting of input and output number, times, and date strings. The locales available, and the level of support for locale features such as "thousands' grouping separator", depend on the internationalization support provided by your individual machine.

External library libcerf versions 1.8 1.9 1.10 return incorrect results for the voigt function. Do not use.