what is HDMI Port and UART port for?

[developer]

Hi,
Does any one know how to use the HDMI port ? I dont see any display when connected and can we use Moi like normal reciever to see channels atleast for testing?
It would be better if we can have a web based remote or an external adapter to connect remote to do see channels or to change if it is possible. Dreambox has a similar feature...
What is the use of UART port?

[diabloss]

after you access webui .... if you set as starting with Matrix TV it will boot into xbmc interface