Hello,
BeeStack is the Freescale’s implementation of ZigBee 2007 stack. It is available for free and it is included I our BeeKit Wireless Connectivity Toolkit. If you are not familiar with it, BeeKit is a standalone software application that provides a graphical user interface (GUI) in which the user can create, modify, save, and update wireless network solutions based on FSL protocol stacks. This powerful tool makes a lot easier the usage of the DEMO applications, including the ones pre-loaded in the kits.
Download link: http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=BEEKIT_WIRELESS_CONNECTIVITY_TOOLKIT
Once generated, you could export the project to the corresponding IDE (Codewarrior for HCS08s and IAR for Kinetis and ARM based MCUs).
Regarding to the hardware solutions, you may use the whole ZIgbee Stack in either the MC1323x devices featuring an 8-bit MCU and a transceiver (SOC) or the brand new MKW2x family of devices featuring a Kinetis ARM Cortex M4 32-bit MCU + Transceiver on chip. This could be what you read about. Please visit our website www.freescale.com/kw2x for further details.
I hope this helps.