Here is the official Minecraft mod plan via notch's blog:
- Let players sign up as “mod developers”. This will cost money (edit: no longer costs money! - see below), and
- will require you agreeing to a license deal (you only need one per mod team).
- Mod developers can download the source code from our SVN repository.
- As soon as we commit a change, it will be available to all mod developers, unobfuscated and uncensored.
- Mod developers get a unique certificate for signing their mods. This means players can see who made what mod and choose to trust individual developers. The cost of signing up makes sure only serious developers have access to this certificate.
The rules of the license deal will contain:
- Mods must only be playable by people who have bought Minecraft
- You can’t sell your mods or make money off them unless you’ve got a separate license deal with us
- The mods must not be malicious (obviously)
- We retain the right to use your mod idea and implement it ourselves in Minecraft. This is to prevent the situation where we have to avoid adding a feature just because there’s a mod out there that does something similar. It’s also great for dealing with bug fixes provided by the community.
In the long term, we hope this means people will do awesome new things with the Minecraft engine and play around with it. We want to buy and/or license good mods and/or total conversions and sell them ourselves. It’s possible we might have a mod marketplace for selling and buying mods that fans have written, or we might purchase and integrate nice mods that fit the main theme of Minecraft.
UPDATE: Cost of the mod api via notch's blog
Because of overwhelming feedback, the cost of the mod api access will be 0 dollars.Our intention wasn’t to make money off selling the access, only to ensure some level of quality. Obviously that wasn’t the most popular idea in the world.
Great to see a commerical game really really think through it's modding strategy and realize the immense benefit robust modding tools and API can bring. We are going to see how closely we can work with Minecraft to provide mods with profiles containing image galleries / videos like they have on ModDB.