The Amazon Kindle is an electronic book reader made and sold by Amazon.com. It was introduced in November 2007, at a price of $399, later lowered to $359. A second version, with more memory and longer battery life, was introduced in February 2009 at the same price. A third, large-screen version, optimized to display textbooks and newspapers, was introduced in May 2009 for $489.

The Kindle uses a display technology called electronic ink, that is meant to mimic the experience of reading black letters on white paper. It is easier to read in bright lights and it uses less electricity than the sort of displays used on laptop computers and cellphones.

A few other companies, notably Sony, also sell electronic book readers. Amazon's approach is different because the Kindle does not need to be connected to a computer. Rather, users can purchase books right on the device, which downloads them over a wireless network. Also Amazon, which is one of the nation's biggest book sellers, has been able to convince most major publishers to release titles for the Kindle. While the Kindle was criticized for its bulky design and lack of features for Web browsing, it has been a hit in some quarters. The device appeals especially to heavy readers who like to travel or just move around town without the weight of several books.

Amazon does not publish sales figures. Estimates of the number of Kindles sold in the first year by industry analysts range from several hundred thousand to one million. Major publishers said that about 1 percent of their titles in 2008 were sold in the Kindle format, which often costs less than a physical book.

In May 2009, Amazon had 275,000 titles for sale in the Kindle format.

The device was praised by Oprah Winfrey, on her show in October 2008. Shortly thereafter, Amazon sold out of the first generation of Kindle devices, missing the critical holiday selling season. The company started shipping Kindles again only in February 2009, when the second generation became available.

Amazon has also said it plans to offer software to read Kindle books on other devices, such as Apple's iPhone. And using a new feature, called Whispersync, users could start reading on a Kindle device and continue from the same spot on their cellphones.

Google has said it plans to get into the electronic book market as well, offering a way for people to read the more than seven million books it has scanned from various devices including phones that use its Android operating system.