CLion is an IDE from JetBrains, the makers of IntelliJ IDEA, Rider, Fleet, WebStorm and several other programming tools. While the recently released Fleet is aimed at Visual Studio Code, CLion is aimed more at the full version of Visual Studio, or more specifically Visual C++. It is built on the same core as IntelliJ and thus shares a very similar user interface, hundreds of extensions and most of the strengths and weaknesses of that platform.
JetBrains CLion is heavily designed around CMake, using that CMakeLists.txt as the standard project format and integrating into open tools such as clang, clang-tidy and GDB/LLDB. One major strength CLion has over Visual Studio is it is cross platform in nature, available on Windows, Mac and Linux. For Rust developers, CLion offers full cargo support.
If you are interested in buying CLion, be sure to check out the special offers link above, as several discounts/free versions exist for a variety of tasks (students/educators/open source contributors/etc.). You can learn more about JetBrains CLion and see it in action in the video below.