Creating a new project vs. co-maintaining an existing project

The Drupal community follows the ethos collaboration rather than competition. Too often new modules are contributed that are very similar to existing modules, just doing the same thing in a different way. We are then stuck with two modules that offer nearly similar functionality, which leads to confusion, clutter, and a lot of inefficiency.

So please consider the following guidelines or ideas:

• Before submitting a new module idea, please do a little research and search for an existing module with the same functionality.
• Develop and use one central API. Do not introduce new .incs, .modules, or other files with APIs, if there are modules that have these already.
• Consult other developers of modules in your domain when you plan to add features, or plan to add a module. Try to agree on features, to avoid overlapping. Nothing is more confusing for a user than when they have, for example a Spam Queue for comments, and a completely different one for trackbacks, which does not respect the options you set for comments. Even worse, but certainly not unheard of, is that module Foo breaks module Bar, because they want to do the same thing, or want to use the same database tables.
• Do not try to duplicate functionality because "you don't really like how it's done there". That only adds clutter. Work to improve an existing module rather than introduce yet another random module, as that leads to confusion and frustration for the development, support and end user communities.

Respecting these guidelines will help you and the community get better. Only then will we be able to "stand on the shoulders of giants" as they say in Open Source Land. If you keep reinventing wheels, you will be stuck with lots of incompatible and half finished wheels. When you use someone else's existing wheel, and build a car on top of it, you can actually get somewhere.

Contributed Module Ideas Group

When a developer has an idea for a module, they are often not the only one with that idea. Post your idea in the Contributed Module Ideas Group before you create a new module, to:

• Reduce module duplication. We can prevent two independent developers from writing separate, duplicate modules.
• Increase developer collaboration. We can get interested developers working together at an early stage of development.
• Improve module quality. Others can shape and improve the ideas, leading to a better module from the beginning (or, at the least, a better road map for future development.)

Document how your module makes a difference

If your efforts to work with an existing project fails, or you decide your idea is different enough to create a new module, you need - at least - to make sure users need to be informed about possible functional overlap. This should be done on your project's project page in a section with the heading "Similar projects and how they are different". Make sure you:

1. Acknowledge the existence of similar projects
2. Briefly explain how your module is different from these other projects