Interactive Rich Media

Amazon CloudFront is a web service for content delivery. It integrates with other Amazon Web Services (mainly Amazon S3) to give developers and businesses an easy way to distribute content to end users with low latency, high data transfer speeds, and no commitments.

Amazon CloudFront delivers the content using a global network of edge locations. Requests for  objects are automatically routed to the nearest edge location, so content is delivered with the best possible performance. Amazon CloudFront works seamlessly with Amazon Simple Storage Service (Amazon S3) which durably stores the original, definitive versions of the files.

In Amazon CloudFront, objects are organized into distributions. A distribution specifies the location of the original version of the objects. A distribution has a unique CloudFront.net domain name  that  can be used to reference an objects through the network of edge locations. It’s also possible to map an own domain name to a distribution.

Amazon CloudFront is

• fast
• simple
• cost-effective
• elastic
• reliable
• global
• designed for use with other Amazon Web Services

The price depends on the edge location and the volume transferred. The mean price per GB for low volumes is about 0,2$, for high volumes about 0,1$. A simple monthly AWS bill calculator is provided by Amazon. Normal fees will apply for Amazon S3 usage, including “origin fetches” – data transferred from Amazon S3 to edge locations.

The edge locations in Europe are:

• Amsterdam
• Dublin
• Frankfurt
• London

Amazon CloudFront is designed for delivery of objects that are frequently accessed – “popular” objects. Objects that aren’t accessed frequently are less likely to remain in CloudFront’s edge locations’ caches. Thus, for less popular objects, delivery out of Amazon S3 (rather than from CloudFront) is the better choice. Amazon S3 will provide strong distribution performance for these objects, and serving them directly from Amazon S3 saves the cost of continually copying less popular objects from Amazon S3 to the edge locations in CloudFront.

OpenID eliminates the need for multiple usernames across different websites, simplifying your online experience. A user can choose the OpenID Provider that best meets his needs and that he trust. The user can keep his OpenID no matter which Provider he moves to. The OpenID technology is not proprietary and is completely free.
OpenID is growing quickly and becoming more popular as large organizations like AOL, Facebook, France Telecom, Google, LiveDoor, Microsoft, Mixi, MySpace, Novell, Sun, Telecom Italia, Yahoo!, etc. begin to accept and/or provide OpenIDs. Today, it is estimated that there are over one billion OpenID enabled user accounts with over 40,000 websites supporting OpenID for sign in.
OpenID was created in the summer of 2005 by an open source community (the father of OpenID is Brad Fitzpatrick) trying to solve a problem that was not easily solved by other existing identity technologies. As such, OpenID is not owned by anyone, nor should it be. Today, anyone can choose to be an OpenID user or an OpenID Provider for free without having to register or be approved by any organization.
The OpenID Foundation was formed to assist the open source model by providing a legal entity to be the steward for the community by providing needed infrastructure and generally helping to promote and support expanded adoption of OpenID.

Two directories are available to see where OpenID can be used to login :

• myOpenID Site Directory
• The OpenID Directory

A Web cache sits between one or more Web servers (also known as origin servers) and a client or many clients, and watches requests come by, saving copies of the responses — like HTML pages, images and files (collectively known as representations) — for itself. Then, if there is another request for the same URL, it can use the response that it has, instead of asking the origin server for it again.

Web caches are used to reduce latency and to reduce network traffic. A very useful tutorial about web caches has been published by Mark Nottingham under a creative common licence.