Panther Express announced the completion of a $15.75 million Series B round of venture financing led by Index Ventures. Gold Hill Capital and existing investor Greylock Partners also participated. Panther will use the funds for international expansion and further infrastructure investment to support its growing list of customers.

Founded in 2005 by Kevin P. Ryan and Dwight Merriman, former CEO and CTO of DoubleClick, Panther combines rapid, reliable and scalable performance with flexible and cost competitive terms resulting in the highest value CDN offering in the industry. In just over two years, Panther has established an international client base of over 250 customers across a broad range of markets including video and audio delivery, podcasting, ad serving, web hosting, gaming, traditional publishers and social networking companies.

Panther's unique network architecture provides the foundation for the industry's leading high performance/high value network. Panther is able to diversify traffic across more than 15 leading ISPs to eliminate single-point-of-failure risk. Panther's proprietary routing technology constantly monitors Internet conditions and all factors impacting delivery worldwide to determine the best data center from which to serve each request for content. Panther's proprietary caching technology is highly tuned for optimal resource usage for all types of content whether large or small. With strategically placed large data centers in key locations around the world, Panther is able to achieve the best cache hit ratios resulting in the best real user performance and the lowest costs to its customers.