CLion is described as 'The intelligent cross-platform C/C++ IDE. CLion is a new IDE that helps you be more productive while developing apps with C and C++ for Windows, Linux and OS X. Take advantage of proven JetBrains expertise in code quality, efficient code navigation, smart code completion' and is a popular IDE in the development category. There are more than 10 alternatives to CLion for a variety of platforms, including Windows, Linux, Mac, BSD and Web-based apps. The best CLion alternative is Visual Studio Code, which is free. Other great apps like CLion are Eclipse, Microsoft Visual Studio, Apache NetBeans and Code::Blocks.
Eclipse CDT is used for C/C++ development, and doesn't require giving out your email address to use it.