On PHPMaster.com today there's a new article with six things that they (well, Daniela Baker) thinks every independent PHP developer should know and have in their arsenal.

PHP development is hot right now, but there are also lots of people in PHP development. If you want to make it as an independent PHP developer you’ve got to know more than just PHP. Here are six other essential skills you need to succeed as a PHP developer.

Her list of six is made up of:

• JavaScript, HTML, and CSS
• Knowing What You Don’t Know
• Business Communication
• Business Finance
• Project Management
• Networking

Really, independent or not, these types of skills/knowledge can help any developer out there to see the bigger picture outside of just their code, out to what the business is doing.