As reported by Phoronix, starting in kernel version 6.7, all support for Intel Itanium architecture (IA64) will be removed. Itanium support in the Linux kernel has waned in recent years. The absence of hardware kernel testers and major active contributors helped contribute to the decision.

The last kernel with Itanium support will be version 6.6 and is expected to be a (LTS) kernel version. Note: For LTS releases, bug fixes are provided for two years, and security fixes are provided for three years. For general kernel releases, bug fixes are provided for six months, and security fixes are provided for one year. 

The Itanium architecture originated at Hewlett-Packard (HP) and was later jointly developed by HP and Intel. Launched in June 2001, Intel initially marketed the processors for enterprise servers and high-performance computing systems. The plan was to be the next generation 64-bit successor, called IA64,  to the popular 32-bit x86 architecture. In the concept phase, engineers said, “We could run circles around PowerPC, that we could kill the x86.” 

In 1999, Linux support became part of the mainline Linux kernel more than a year before the release of the first Itanium processor due to GCC having been enhanced to support the Itanium architecture, and a free and open source simulator had been developed to simulate an Itanium processor.

The Itanium architecture never gained momentum, largely due to delays and the complexity of creating software for VLIW compilers and tools. In addition, in 1999, the emergence of the AMD x86_64, a 64-bit extension of the x86 32-bit design that was backward compatible with 32-bit x86, stifled any real growth of the Itanium IA64 architecture. In 2004, Intel announced that it would support AMD x86_64, which found its way into the Nocona Xeon processor.