To conform to GPL rules, the OctaneRender® for Blender® plugin consists of two parts:
OctaneServer® is the server for getting the TCP/IP render-commands and scene data from the client, rendering the scene, and returning the rendered image to the client.
The Blender – OctaneRender® edition is the special compilation of Blender®, which includes the internal OctaneRender® module. The module collects the Blender® scene data and communicates with the OctaneServer® as the client by sending the data to the server, getting the rendered image from it, and showing that image to you. Such a way GPL is not violated by OctaneRender® for Blender Plugin: as the source-code of Blender – OctaneRender® edition (which is under GPL) is available for users of the Plugin, and the source-code of Otoy‘s proprietary closed-sourced OctaneServer® does not need to be published, as OctaneServer® is not linked to Blender and works with render-clients through TCP/IP communication.