The One X is HTC's flagship phone for the first half of 2012. It features a highly-acclaimed Super LCD2 720p screen, which many consider to be the best display on a mobile phone to date. The international version of the One X ships with a quad-core Nvidia Tegra 3 CPU processor that is backed by a full gigabyte of RAM and 32 gigs of flash memory. The device's software is also notable. The One X comes pre-loaded with Android 4.0.3, featuring the HTC Sense 4 user interface, which marked the slimming of their previously heavy custom skin.
How to root the HTC One X

1. Download and install the HTC mobile phone drivers. [Windows]

2. Download the file.

3. Extract into a directory on your computer.

4. Plug your HTC One X into your computer via USB. Recommended: Plug your device’s USB cable into the back of your computer if you’re using a desktop PC.

5. Enable USB Debugging on your HTC One X. Settings >> Developer Options >>USB debugging (checked)

6. Double click root.bat/ to run the script.

See more here

Congratulations! Your device will reboot a number of times and then you will have full root access.
Kernels : HTC One X
Tools/Utilities : HTC One X
Rom List : HTC One X