I have a commercial plugin that operates within an open source application licensed under the GPL. Most of my source code will be legible, however, the plugin will get an activation token from an external executable that validates the license key the user received on purchase from my web site. Am I legally required to share the source code of the external executable?
Thank you.
If the plugin communicates with the external executable via TCP or some other inter-process communication, the external executable would not be subject to the viral effects of the GPL.
However, since the plugin is open source under GPL, someone could modify its source code to remove the license key check and recompile it, thus circumventing your license key check, and thus fulfilling GPL's promise of having truly free software (free as in freedom of speech).
