Linux just keeps popping up on many of the popular gadgets that are hogging the limelight nowadays. Some are quite conspicuous about it, like the Android phone that is being developed by a group that makes it very obvious, calling themselves the Open Handset Alliance. However, there are some that don't flaunt Linux around, like the Amazon Kindle. Not that they have to, but well, allow me to do it for them here anyway.

What's there to flaunt?

"To flaunt" is synonymous to "to display", so let's take it from there. The Kindle is just one of a number of eBook readers that have been popularized by their distinctive displays, operating on a technology named electronic paper or e-paper. Uh-huh, E-paper... WHICH IS? Ok, E-paper is a type of display that has two essential features: an appearance that closely mimics that of ink on paper and an energy consumption that is substantially lower than those of conventional displays like CRT or LCD. So why would you want to have a display that is just like, well, ordinary paper? The answer is pretty simple; ordinary if you like: think eyestrain. How long can you peer into that CRT monitor or even an LCD screen before your eyes start telling you that it's had enough? Not longer than you could when reading from a book, right? The reason lies in the fact that reading from paper makes use of reflective light while reading from a conventional screen is practically reading from the light source itself; backlight remember?

Largely because of this feature, practically all of the popular eBook readers make use of this technology. Yes, yes, but where does Linux come in? Well, most of these readers run on the Linux operating system. Below is a list of the more popular eBook readers operating on e-paper technology and at the same time running Linux.

Arguably the most popular eBook reader, this device would top this list even if it were not alphabetically arranged. While it may not hold the largest display area, at 6" diagonally, its ability to download eBooks from Amazon has made it an overwhelming favorite.

Talk about file format support: pdf, mobi, prc, epub, lit, txt, fb2, doc, html, rtf, djvu, wol, ppt, mbp, chm, bmp, jpg, png, gif, tif, rar, zip, mp3. Talk about built-in language support: English, French, Spanish, German, Dutch, Chinese, Russian, Greek, Ukraine, Turkish, Japanese, Korean, Bulgarian, Estonian, and Polish.

This device is stocked with a built-in dictionary lookup; one feature that the other readers on this table are not endowed with. Note taking is also made easier with its bookmark menu. At 0.9 s, it provides one of the faster full-screen refresh rates, resulting in a more seamless reading experience.

One of the thinnest, at 3"; one of the longest battery lives, serving up to 10,000 page turns per charge; one of the fastest boot up times, at 15s; and one of the lightest at 176g. This eBook reader is packed with superlatives. And to top it all, price isn't one of them.

Not much has been written about this particular eBook reader. Some of the known features are: a primary display with 8 levels of gray, a higher contrast, and a faster display (although no number has been specified). One notable description is its striking resemblance with the STAReBook (shown directly above).

This reader has one of the better batteries in the lot, allowing you to turn 9,000 continuous pages on a single charge. Supports SD/MMC expansion memory. Also supports a wide array of file formats: PDF, TXT, RTF, EPUB, LIT, PPT, WOLF, DOC, CHM, FB2, PRC/MOBI, HTML, DJVU, MP3, TIFF, JPG, GIF, BMP, PNG, RAR, ZIP.

Tied with the iRex Digital Reader, this device tops this list in terms of screen size, at 10" when measured diagonally. It has a touch panel, which is one of its best qualities, and can support the ff formats: PDF, DOC, WOLF, HTML, JPG, TXT, CHM, RAR, ZIP, and other image files.

Also fitted with a 10" screen, it is one of two of the largest in this class. And like that other large screen reader, it allows you to make handwritten notes onscreen just like an ordinary pen and paper combo. This device however is equipped with WIFI and Bluetooth connectivity.

While it does not have a colored display, it is one of the more graphically-empowered readers with 16 gray levels. The same screen also allows user interaction through a touch-sensitive surface. It offers an SDK, allowing users to port or develop a number of Linux apps.

This device comes equipped with a front light that can come handy when a backup light source is needed. It is one of the thinnest in this class, coming in at a sexy 0.4". Its touchscreen surface allows user interaction through a finger or a stylus.

If you're interested, you can play around in an environment that closely mimics these devices. E-ink, the company that supplies the displays for almost all of the devices mentioned above provides a prototype kit with a host system that comes with a pre-installed Linux operating system. Yes, that means it's pretty hackable. If you want to see how Linux runs on paper, electronic paper that is, I suggest you give it a shot... and don't bother to take out your pen.