Datahead implements CoAP-based data collection.
From a command line:
$ python collector.py
Datahead generates a log file, datahead.log.
Datahead is released under the Mozilla Public License, 2.0. Our intent is that the content of the files we have developed must remain freely available. If you redistribute those files, you must share any changes you have made to them. Please send us your fixes and improvements so everyone benefits!
On the other hand, it's perfectly fine to add proprietary files to Nethead as an application that you redistribute, within the requirements of the license. Give it a read, or see the Wikipedia article to get started.