The GNU plotutils package contains software for both programmers and
technical users. Its centerpiece is libplot, a powerful C/C++ function
library for exporting 2-D vector graphics in many file formats, both vector
and raster. It can also do vector graphics animations.
libplot is device-independent in the sense that its API (application
programming interface) does not depend on the type of graphics file to be
exported.
Besides libplot, the package contains command-line programs for plotting
scientific data. Many of them use libplot to export graphics.
The current version is 2.4.1, released July 2000. It can be installed on
GNU/Linux, FreeBSD, and Unix systems.
GNU libplot, and applications built on it, can now export graphics
files in SVG format. SVG (Scalable Vector Graphics) is a new,
XML-based format for Web graphics, which is being standardized by
the Graphics Activity of the W3 Consortium.
PNG format can now be exported too!
The libplot API has been extended to support the drawing of
Postscript-style compound paths.
The plotutils package comes with a 175-page manual. Here is an older
version of the manual.
The package is free software. Its source code is distributed as a gzipped
tar file, 3.3 megabytes in size. Here is how you can get it.