Last system I worked on with GHS Integrity was something like a USD $1M+ licensing fee. In terms of usage, it felt like it was in between an RTOS like FreeRTOS

Last system I worked on with GHS Integrity was something like a USD $1M+ licensing fee. In terms of usage, it felt like it was in between an RTOS like FreeRTOS, embossed, or Zephyr, and Linux. It used a lot of best practices like statically allocating memory for basically everything, so you knew you had sufficient memory (at least for anything the OS needed) when your application was loaded.