CoreCtrl is described as 'Free and Open Source GNU/Linux application that allows you to control with ease your computer hardware using application profiles. It aims to be flexible, comfortable and accessible to regular users' and is an app in the System & Hardware category. There are more than 10 alternatives to CoreCtrl for a variety of platforms, including Windows, Linux, Android, iPhone and Mono. The best alternative is Open Hardware Monitor, which is both free and Open Source. Other great apps like CoreCtrl are MSI Afterburner (Free), SpeedFan (Free), ASUS GPU Tweak III (Free) and GreenWithEnvy (Free, Open Source).
This software detects and optionally controls speed of CPU fan of many PC-Systems. Furthermore you are able to configure the handling of the EC-registers on your own (risk). To determine the EC-registers use e.g. software like "rw everything".