Device-driver libraries are libraries which are built as part to the PLplot build and which are linked by PLplot device drivers. At this time we only have one example of this, the NIST cd library which makes it easy to create files in CGM format. The original name of this library was libcd, but we call it libnistcd to distinguish it from all other "cd" libraries out there. This library is linked by our cgm device driver.

CGM format is a long-established (since 1987) open standard for vector graphics (see http://www.w3.org/Graphics/WebCGM/). The libnistcd software was developed by G. Edward Johnson at NIST to provide convenient access to the CGM format. The library is no longer maintained (the last official release was in 1997), but the software is mature and works well. Furthermore, it is in the public domain except for the small part licensed under the libgd open-source license (see lib/nistcd/cd.html in the PLplot source tree). PLplot developers have added a modern CMake-based build system for libnistcd and also have done some visibility support so the code builds properly under Windows and also under Linux with gcc when the -fvisibility=hidden option for gcc is used. Otherwise, the code is identical to the 1997 version. For documentation of the libnistcd API see lib/nistcd/cd.html in the PLplot source tree.