# External libraries

External library GD (used by PNG/JPEG/GIF drivers): Versions of libgd through 2.0.33 contain various bugs in mapping the characters of Adobe's Symbol font. Also it is possible to trigger a library segfault if an anti-aliased line crosses an upper corner of the canvas.

External library PDFlib (used by PDF driver): 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.

External library svgalib (used by linux and vgagl driver): Requires gnuplot to be suid root (bad!) and has many bugs that are specific to the video card or graphics driver used in X11.

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.