Another modern C++ compiler released by IBM, based on a modern foundation:

New C/C++ compiler for Linux on z Systems

Today, IBM announced a brand new C/C++ compiler for Linux on z Systems. Built on top of the advanced optimization technology already in use by the Java and Enterprise COBOL compilers, the XL C/C++ for Linux on z Systems compiler generate highly optimized code to significantly improve runtime performance of applications. It leverages the Clang open source infrastructure for a portion of the compiler front end resulting in a high level of source compatibility with GCC and includes partial support of the latest C11 and C++11 language standards. In addition, the XL C/C++ for Linux on z Systems is able to exploit the new z13 hardware announced today through the use of the qarch and qtune suboptions. High performance mathematics libraries, MASS (Mathematical Acceleration Subsystem) and ATLAS (Automatically Tuned Linear Algebra Software) will also be packaged with the compiler and made available for the first time on zLinux.

The XL C/C++ for Linux on z Systems V1.1 runs on RHEL 6, RHEL 7, SLES 11, and SLES 12 and will become generally available on February 16, 2015. For more information on this new compiler, visit the XL C/C++ for Linux on z Systems product page.