I want to program my own bootable USB Stick, that means creating an iso which I can "burn" to my USB stick via unetinboot. I know there are many lightweight linux distros out there, but I just need to mount the HDD and do some basic file operations. Copy, replace and such. And I want to display something on the computer's screen.
Which programming language is used to create such a "program"? Are there libraries which I can use? Any other ideas?