VSCP & Friends (http://www.vscp.org) is an open source solution for a m2m/IoT user level protocol for Linux /Windows and many lower level hardware platforms. The goal has been to build a solution that can
1.) detect a new device in an environment containing units that use different lower level protocols in a common way,
2.) get the capabilities of a new device in a common way.
3.) make it possible to tell what the new device should do (configure it) in a common way.
4.) make devices using different lower level protocols play togehter.
5.) update firmware in a common and secure way on different devices.
Software and firmware and samples are available that realise most of this.
Specification is here http://www.vscp.org/docs/vscpspec/doku.php
Description of higher end system software is here http://www.vscp.org/docs/vscpspec/doku.php
Description of software lib is here http://www.vscp.org/docs/vscphelper/doku.php?id=start
Firmware descriptions are here http://www.vscp.org/docs/vscpfirmware/doku.php
Docs for user interface components are here http://www.vscp.org/docs/html5/doku.php
ode is here https://github.com/grodansparadis/vscp