Developers of Substrate, a technology that allows developers to make targeted modifications of software on mobile devices.
Operators of Cydia, the "alternative to apps" on jailbroken devices (currently, Apple's iPhone, iPad, and iPod touch platforms).
Maintainers of JailbreakQA, the community-run site to get help with questions about modifying your Apple mobile device.
SaurikIT, LLC is owned and operated by Jay Freeman, known by many people online as "saurik". He has a blog/website.