Examples of popular, commercial applications written in PHP?

Question

I was just curious to see if I could get together a list of some popular, commercial applications written with the PHP language. I'm just curious what people have built using PHP and how well it seems to fit the application they've developed.

Some I know of are:

1. ModernBill
2. WHMCS
3. vBulletin

What else is out there?

EDIT: To clarify, I'm looking for resalable commercial applications you can purchase. i.e. think "I purchased a copy of Microsoft Windows" not "I used the Google search engine."

Answer 1

How about Facebook? I hear that's popular these days.

Answer 2

Not really a commercial app but Facebook is PHP based. If you are concerned about the load and ability to support many users I think that is a good example.

Answer 3

Digg.com and Wordpress would both be a pretty large players.

Answer 4

Magento - an eCommerce package

Answer 5

ExpressionEngine is written in PHP, pretty popular blogging engine.

Edit: Oh, and don't forget the site-tracker Mint and the RSS-reader Fever.

Answer 6

Quoting from Wikipedia:

As of April 2007, over 20 million Internet domains had web services hosted on servers with PHP installed and mod_php was recorded as the most popular Apache HTTP Server module. Significant websites are written in PHP including the user-facing portion of Facebook, Wikipedia (MediaWiki), Yahoo!, MyYearbook, Digg, Joomla, WordPress, YouTube in its early stages, Drupal, Tagged and Moodle.

Answer 7

Well this isn't exactly an answer but a reply to Salgar's comment (Since I joined fairly recently and don't yet have enough reputation to make comments - and it may even be worth a few downvotes - but I couldn't let this go and I hope he was being sarcastic):

Yeah, I heard everyone at facebook works for free, its more of a movement than a company.

I could argue for three thousand hours about this statement but here is one simple link to prove how rubbish it is: http://www.facebook.com/#/careers/?ref=pf. If you want to find this link you can go to the Facebook homepage and scroll to the bottom where on the right hand side you will see a link "Careers."

In fact I don't think any one at all works at Facebook for free, well maybe Mark Zuckerberg does.

Answer 8

Cube cart is another one.

Answer 9

Timely find I made here:

10 years of PHP Applications that changed the world

http://blog.fedecarg.com/2008/05/22/open-source-php-applications-that-changed-the-world/

Did you mean not-open-source or did you mean money-making companies?

Answer 10

I really like activeCollab. It's a project management and collaboration tool.