From ChipKit Wiki
The chipKIT™ Platform is an open-source hardware and software solution intended for beginners and users who wish to explore embedded applications with little or no knowledge of embedded controllers.
 Mission Statement
The chipKIT™ Environment advances the art of open-source physical computing by expanding support to more chip platforms and introducing new, high-performance libraries. It combines low-cost hardware with free software that is fast, powerful, and extendable. Inspired by Arduino™, chipKIT controller boards and software tools are easy to use by beginners of any age and specialists in any field. These boards and tools are compatible with standards established for the hobbyist community and also offer a clear migration path to professional-grade tools for experienced engineers.
 Multi-Platform Integrated Development (MPIDE) Download and Source Code
The software environment is created in Java and based on the Processing programming language.
The open-source Multi-Platform Integrated Development (MPIDE) runs on Windows, Mac OS X, Linux and can be downloaded directly from here.
Source code for the MPIDE software is hosted by GitHub and is available here.
 Licensing the chipKIT™ Name
The chipKIT™ Name is trademarked by Microchip Technology but is available for licensing at no charge to parties wishing to build their own chipKIT™ boards.
Licensing agreement is obtained by emailing a request to Microchip Technology at chipKITlicensing@microchip.com. Upon receipt, requests will be reviewed and the license agreement sent electronically for review and signature.