Open64 is a compiler infrastructure project that provides a high-performance, production-quality optimizing compiler for various architectures. It was initially developed by SGI (Silicon Graphics, Inc.) and was later released as an open-source project under the GNU General Public License (GPL).

Open64 is designed to support multiple programming languages and target different platforms, including 32-bit and 64-bit systems. It includes a suite of compiler tools, such as a frontend for parsing and analyzing source code, an optimizer for code transformations and performance improvements, and a backend for generating machine code for the target architecture.

The project aims to provide a robust and extensible compiler infrastructure that can be used as a foundation for building custom compilers and tools. It has been used in various research and development projects, as well as in commercial products.

It’s worth noting that Open64 has not seen active development for some time, and its last major release was in 2012. Since then, other compiler frameworks like LLVM have gained significant popularity and have become more widely used in the industry.