OpenGL / Dolphin System
The 'OpenGL / Dolphin System' references the leftover .exe file left in all retail GameCube Pikmin discs.
The name comes from when you open the .exe in the command prompt with the command "sysBootup.exe +output". This will create a UI for you that you can run different "modules" from. The name of the window that's created is called "OpenGL / Dolphin system". The reason for this may be that the developers of Pikmin made the game side-by-side with Windows programs for debugging and testing all of the formats and the game itself.
The file formats and other peculiarities of Pikmin leads us to a conclusion that the developers of the game used a very very old form of the J3D toolchain, a code library used to create Super Mario Sunshine and Pikmin 2. Could the "OpenGL / Dolphin System" be an old version of the toolkit tailored towards Pikmin?