Firmata and Linux

I have made this http://woodnotoil.googlepages.com/arduino controller for my heating system and it works great so far. Now I would like to make a piece of software to monitor the temperature sensors and relay. Right now I can monitor it using the arduino serial monitor, but would like something that looks a little better than that.

I was thinking of using firmata but I am confused by the documentation on the arduino site. I have version 12 and it says it is already in there. Does that mean all I need to do is put the firmata functions in like in the example here http://arduino.cc/en/Reference/Firmata ? or is there something else I need to download and install.

Also, what flash tools are people using to write flash on linux? Anyone have examples of flash programs they have made to send and recieve to arduino? Thanks