PREEMPT_RT was a set of patches for the Linux kernel which implement both hard and soft real-time computing capabilities.
[1] On September 20, 2024, PREEMPT_RT was fully merged and enabled in mainline Linux on the supported architectures x86, x86_64, RISC-V and ARM64.
[5][6] Since February 2023, Canonical has been releasing real-time versions of Ubuntu Pro, free for personal and small-scale commercial use in up to 5 machines.
Montavista's current main embedded Linux product, CGX, contains real-time preemption as a standard feature.
At the September 2024 European Open Source Summit, Linus Torvalds announced that PREEMPT_RT had been accepted into the mainline linux kernel after a protracted development hurdle involving the printk kernel logging facility.