Powerful and expandable, this open source CMS is known for high scalability, flexibility and best for SEO.

Technology it’s based on: PHP

Pros: It’s free, good for SEO, easy installation, highly modular, secure, good access control

Cons: Not for beginners, hard to learn the entire system, some systems (such as categories) are very complex.

Cost-wise: it’s free, but you have to either be an expert to build a complex website on it, or you need an expert to do the hard core coding for you.

Best plug-ins for enterprises: ecommerce, clone, Image, Drupal SEO Checklist module.