A popular IDE for Arm-based MCUs from various vendors to use for C++ embedded programming

Hi all,

As a C++ programmer I would like to start using it in the embedded world. For that I wish to be familiar with a popular IDE on which I can write projects for ARM-based MCUs, from different vendors, be it of ST or others, and get help when running across a problem. 

I've some titles in mind such as: IAR and Keil. What are your ideas, please?

Thanks.