This addon is outdated, it has been supplanted by https://github.com/z64tools/io_export_so2
This is a .obj exporter aimed at exporting for SharpOcarina, for Zelda64 modding.
It supports vertex colors and is more robust than other exporters.
See also Simple Material Helper: https://github.com/Dragorn421/SimpleMaterialHelper
Download the export_obj_so.py
file from releases: https://github.com/z64tools/export_obj_so/releases
Install that export_obj_so.py
file as an addon.
For how to install addons, see the Blender manual: https://docs.blender.org/manual/en/latest/editors/preferences/addons.html