I have been involved in several Open Source projects, some of which have been successful and some... less successful. I really enjoy starting new projects but absolutely hate maintaining and documenting the old ones, to the extent that someone even implied that I am allergic to documentation.

There are a few ingredients that make a project successful, the most important being a good idea. An idea can be a tool or a library that you need and think others might find useful; a new technology innovation; or something you think you could implement better than the existing tools. Extra care has to be taken if you decide to create a new tool to replace an old one. In most cases, these projects end up reinventing the wheel without any added value. A wheel is wheel, right? But of course there are exceptions. One of these exceptions is Magento [1]. It's an e-commerce tool in PHP that
does things differently: PHP5 only, uses a framework (ZF) and the code is nice and clean. A good implementation makes it easier to attract skilled developers to contribute to the project and to build a community around it.