The barcode package is mainly a C library for creating bar-code output files. It also includes a command line front-end and (in a foreseeable future) a graphic frontend.
The package is designed as a library because we think the main use for barcode-generation tools is inside more featured applications. The library addresses bar code printing as two distinct problems: creation of bar information and actual conversion to an output format. To this aim we use an intermediate representation for bar codes, which is currently documented in the ps.c source file (not in this document).
Note that the library and the accompanying material is released according to the GPL license, not the LGPL one. A copy of the GPL is included in the distribution tarball.