Nintendo
Nintendo is accessed through the Nintendo Developer Portal. You apply as a company, wait for approval, then get access to the SDK, documentation and dev kits for Nintendo consoles.
To be evolved. I have no first-hand experience launching on Nintendo, the information is general. This section will be completed by a developer with real experience.
In short
- You apply at developer.nintendo.com as a developer/company.
- Approval-based process, Nintendo evaluates the request before granting access.
- After approval: NDA, SDK, documentation and Nintendo dev kits.
- The game goes through certification (lot check) before launching on the Nintendo eShop.
See also Console Platforms for the general context.