Disclaimer: IANAL.
CF-Lite (the opensource part — some part of CoreFoundation is close sourced) is licensed in APSL 2.0. You can link to CF-Lite for propriety software:
2.1 Unmodified Code. You may use, reproduce, display, perform, internally distribute within Your organization, and Externally Deploy verbatim, unmodified copies of the Original Code, for commercial or non-commercial purposes, provided that in each instance: (you should include the copyright and license etc.)
But you have to document and publish the changes of the source code for the users, if you modify CF-Lite:
2.2 Modified Code. … (c) If You Externally Deploy Your Modifications, You must make Source Code of all Your Externally Deployed Modifications either available to those to whom You have Externally Deployed Your Modifications, or publicly available. …