Join forces with others

Too often new modules are contributed that do nothing new, instead, they only do it in a different way. We are then stuck with two modules that offer nearly similar functionality, but neither do it well enough. This leads to confusion, clutter, and a lot of inefficiency.

So please consider the following guidelines or ideas:

• 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 when he has, 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, 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.