The computer where the application will be made is on ubuntu 14.04 but the application should run on a sbc6000x board (linux 2.6.24). It would be to make a simple buttons/message box to begin with.

Thank you for the future answers !

Qt the free version
FLTK
GTK

Hopefully you received some documentation and the linux tool chain with your SBC. And hopefully there is some information on how to configure it.

Do you have a display that goes with the SBC?

This SBC uses a atmel micorcontroller as its cpu. And has a controller for LCD/Touchscreen. Is it right?
You have to first make atleast a framebuffer capable graphics hardware. Then make a driver for that framebuffer and then use X Windows or Wayland.

And then the above post suggesting GTK+, Fltk, Qt matters

Perhaps making a console driver is good start.

Perhaps One LQ member smeezekitty has developed one. Please search LQ for that.

Thanks i will take a look.

I have some documentation and a display but nothing in the documentation is explaining anything about the display...i know it is working because the system boot and the resolution is 480*272, this is all i know.

I will be honest, i am kind of lost in all of this. I will try to search about this and contact this person.

My best recommendation is to use the default demo distribution they've given you and try to develop UI software within their demo model. They have forums which do not appear to be too active, but are at least a resource to try. This is their support page http://embest-tech.com/technical-supports/

For instance, a Beaglebone Black board with an attached LCD feature will boot into an XServer and then someone can use any of the earlier recommended packages to develop some UI. I would hope with this board, a similar capability would exist, or instructions as to how to run a demo at the very least.