PC/SC is a standard proposed by the PC/SC workgroup http://www.pcscworkgroup.com/ which is a conglomerate of representative from major smart card manufacturers and other companies. This specification tries to abstract the smart card layer into a high level API so that smart cards and their readers can be accessed in a homogeneous fashion.
This toolkit was written in ANSI C that can be used with most compilers and does NOT use complex and large data structures such as vectors, etc. The C API emulates the winscard API that is used on the Windows platform. It is contained in the library libpcsclite.so that is linked to your application.
These details are provided for information only. No information here is legal advice and should not be used as such.
At one point, Open Hub analyzed source code for this project based on code location(s) available at that time. Since then, the code locations have been removed.