A GPL linking exception modifies the GNU General Public License (GPL) in a way that enables software projects which provide library code to be "linked to" the programs that use them, without applying the full terms of the GPL to the using program. Linking is the technical process of connecting code in a library to the using code, to produce a single executable file. It is performed either at compile time or run-time in order to produce functional machine-readable code. There is a public perception, unsupported by any legal precedent or citation, that without applying the linking exception, code linked with GPL code may only be done using a GPL-compatible license. The license of the GNU Classpath project explicitly includes a statement to that effect.