There are many advantages to hiring an X Window System developer. One advantage is that the X Window System is a very popular windowing system and therefore developers who are familiar with it can be very valuable to companies. Another advantage is that the X Window System is very customizable and allows for a lot of flexibility in terms of how applications are designed and laid out. This can be extremely beneficial for companies who want to create unique applications or who need to tailor their applications to specific user needs. Finally, the X Window System is very stable and has been around for many years, which means that developers who are familiar with it can be trusted to work on mission-critical applications without fear of instability or data loss.