Adobe AIR
From MobileRead
The Adobe® AIR® runtime enables developers to package the same code into native apps for Windows and Mac OS X desktops as well as iPhone, iPad, Kindle Fire, Nook Tablet, and other Android™ devices, reaching the mobile app stores for over 500 million devices.
[edit] Overview
Adobe Air is the Adobe equivalent of Microsoft .net framework. It has an SDK available for programmers. Tools used to read and convert eBooks are sometimes written using this SDK.