centos-release-scl In order to gain access to SCLs for CentOS, you need to install the CentOS Linux Software release file. It is part of the CentOS Extras repository and can be installed with this command: yum install centos-release-scl
SCL From wikipedia, Software Collections (SCL) is a CentOS repository that provides a set of dynamic programming languages, database servers, and various related packages. devtoolset-7-gcc* devtoolset-7 - Developer Toolset is designed for developers working on CentOS or Redhat Enterprise Linux platform. It provides current versions of the GNU Compiler Collection, GUN Debugger, and other development, debugging, and performance monitoring tools.