This is only an issue if you're buying e-books from Amazon. There are plenty of wonderful texts available in the public domain, already formatted for the Kindle [0,1], and plenty of other options for public domain texts in other supported formats [2,3].
But regardless, the Kindle natively supports PDF, HTML, and plain text, and should you want to, Amazon provides a tool to convert those and other formats (including ePub) to the Kindle's proprietary mobipocket-derived format. They even provide Linux binaries [4].
Don't want to deal with conversions and manually managing your library? Just use Calibre [5]; it's open source.
And that's exactly why I placed my order: I'm not willing to accept Amazon's DRM, which will force me to read older works to get value out of the device. A goal I've had since reading a quote dubiously attributed to Einstein: "Somebody who only reads newspapers and at best books of contemporary authors looks to me like an extremely near-sighted person who scorns eyeglasses. He is completely dependent on the prejudices and fashions of his times, since he never gets to see or hear anything else."
The quote is not so dubiously attributed, here's how it appears in his "Ideas and Opinions" 1954, Crown Publishers:
"ON CLASSIC LITERATURE Written for the Jungkaufmann, a monthly publication of the Schweizerischer Kaufmaennischer Verein, Jugendbund, February 29, 1952.
Somebody who reads only newspapers and at best books of contemporary authors looks to me like an extremely near-sighted person who scorns eyeglasses. He is completely dependent on the prejudices and fashions of his times, since he never gets to see or hear anything else. And what a person thinks on his own without being stimulated by the thoughts and experiences of other people is even in the best case rather paltry and monotonous.
There are only a few enlightened people with a lucid mind and style and with good taste within a century. What has been preserved of their work belongs among the most precious possessions of mankind. We owe it to a few writers of antiquity that the people in the Middle Ages could slowly extricate themselves from the superstitions and ignorance that had darkened life for more than half a millennium. Nothing is more needed to overcome the modernist's snobbishness."
But regardless, the Kindle natively supports PDF, HTML, and plain text, and should you want to, Amazon provides a tool to convert those and other formats (including ePub) to the Kindle's proprietary mobipocket-derived format. They even provide Linux binaries [4].
Don't want to deal with conversions and manually managing your library? Just use Calibre [5]; it's open source.
And that's exactly why I placed my order: I'm not willing to accept Amazon's DRM, which will force me to read older works to get value out of the device. A goal I've had since reading a quote dubiously attributed to Einstein: "Somebody who only reads newspapers and at best books of contemporary authors looks to me like an extremely near-sighted person who scorns eyeglasses. He is completely dependent on the prejudices and fashions of his times, since he never gets to see or hear anything else."
[0]: http://manybooks.net/
[1]: http://www.feedbooks.com/
[2]: http://classics.mit.edu/
[3]: http://www.gutenberg.org/
[4]: http://www.amazon.com/gp/feature.html?ie=UTF8&docId=1000...
[5]: http://calibre-ebook.com/