Amazon.com announced two enhancements to its Linux-based Kindle e-book reader, offering 85 percent more battery life, as well as a native PDF reader. The Kindle can now last seven days even with wireless turned on, claims Amazon, which is offering the enhancements to current users via firmware upgrades.

The enhancements apply only to the 6-inch screen Kindle 2 (pictured at right), which is now referred to simply as the Kindle, replacing the earlier version. They do not apply to the 9.7-inch Kindle DX.

The new Kindle firmware is touted as offering a week of battery life with wireless activated, and it continues to offer two weeks of life with wireless turned off, says Amazon.com. The battery life improvements are said to be the result of a six-month firmware improvement and testing program.

The 6-inch Kindle answers another wish-list item by adding a native PDF reader. Kindle customers can email PDFs to their Kindle email address or transmit them to the device via USB. Customers can also still choose to convert their PDF documents to the Kindle format by typing "Convert" in the subject of the e-mail when sending documents to their "@kindle.com" address, says Amazon.

In the coming months, Amazon's market-leading Kindle should see some formidable competition in the e-reader market, most notably from Barnes and Noble's Nook. Yet, according to a recent eWEEK story, the Kindle will pretty much have the holiday season to itself. The Nook (pictured at left), which is now available for pre-order, has slipped to a January ship date, due to "high demand," says the story.

Meanwhile, Sony's new Sony Reader, which could also prove troublesome for Amazon, is expected to ship between Dec. 18 and Jan. 8, but the Sony Reader site now says that delivery dates cannot be guaranteed. (We suspect that based on Sony's past devices, the Reader incorporates embedded Linux, but the company is staying mum for now.)

If these two contenders can't knock the Kindle down to size, two more spiffy looking Android-based e-book readers, are on the way in the first quarter. Entourage Systems will launch the Entourage Edge, and Spring Design will ship the Alex.

Availability

The new Kindle is now available for shipment, here, says Amazon. Existing Kindle 2 owners can update their firmware for the new capabilities via the Whispernet wireless service. Native PDF support will also be available for some earlier versions of Kindle via an automatic Whispernet firmware update.

The eWEEK story on the Nook delays may be found here.

This article was originally published on LinuxDevices.com and has been donated to the open source community by QuinStreet Inc. Please visit LinuxToday.com for up-to-date news and articles about Linux and open source.