Mike-

You can control my software with external tools by providing a startup script - I include Matlab and Python examples on the wiki
  https://www.nitrc.org/plugins/mwiki/index.php/surfice:MainPage#Scripting_from_Matlab
but the methods will work for any language that allows you to invoke separate programs. You can sort of run it in headless mode by using the 'quit' command to terminate the program once it has generated an image. However, even in this approach the graphical user interface will (briefly) pop up while it runs your script - it is using your computers' graphics card and display properties.

-c