The Neo is a more affordable version of the Galaxy Note 3 that comes with a few compromises, most notably regarding its screen and camera. Samsung officially announced the handset at the end of last month and eventually revealed that it would not come to the US or the UK, but it would still be available in many other markets across the globe. The Neo hasn't launched yet, but Samsung has now made the device's kernel source files available to all.
The N750 is the Neo, whereas the N7505 is the Neo LTE. Look for more information about the device to show up at Mobile World Congress in Barcelona next week, but in the meantime, developers, have at it.