Joel Liu's Library tagged converter →  View Popular, Search in Google

He is developing Savory, the first native Kindle application. Savory is an open source epub and PDF converter that actually runs natively on the Kindle. While it doesn't add anything that you couldn't do from a desktop, it streamlines the process, allowing you copy epubs and PDFs to your Kindle over USB or download them from the web, and immediately read them offline. (O'Reilly provides bookworm, which converts DRM free epubs to HTML and lets you read them through the Kindle's web browser, as well as DRM-free .mobi formatted versions of much of O'Reilly's catalog at O'Reilly Ebook Bundles.) Here's Jesse on why he created Savory:

I'm in love with my Kindle. I've been reading ebooks on screens of various sorts for many years, but the Kindle2 is the first device that I actually enjoy reading as much as I enjoy reading paper books. I've tried other ebook readers, but for a variety of reasons, they just don't work for me. My goal is to make it easier for readers to read more free content on the Kindle.

Savory is based on the open source project Calibre -- a python application that lets you convert between multiple ebook formats. The implementation is a background daemon that uses inotify to immediately convert the file to the mobi format. To get a performance boost, it uses unladen-swallow -- Google's optimized version of Python. I find it exciting that this paves the way for 3rd party applications on the Kindle.