as mentioned MQTT is a great way to interface with openHAB. I understand that you are looking to promote your Powerboard with the ability to be controlled by openHAB among others. I would love that! Integration is actually quite easy.
Besides an installation of either openHAB (v1.x) or the soon to be finalized openHAB 2.0 beta, you just need to install the MQTT Binding.
In the community you can find many examples on how to configure a minimal working setup to communicate with an MQTT device to set and read states. If you need help with that, don’t hesitate to ask.
I saw that your device can both switch power and send usage statistics for multiple sockets. All of that can be represented by openHAB in simple items and displayed as visual switches / info texts. I do not see any complicated steps here. is there any other information or logic you would like to see openHAB working with? openHAB is very flexible and for example can do this with your readings.
One last thing you might want to consider: The openHAB MQTT binding expects status info as either
ON. If the status send by your device is different, an transformation has to be used in openHAB. Not a problem but a nuisance… Link 1, Link 2.
Btw. I really like your product and will look into backing you.