[kazinator]

Many operating systems that use manual memory allocation and/or reference counting techniques are nevertheless unsuitable for real time.

Modern desktop and mobile device operating systems often exhibit embarassing lulls in responsiveness that resemble pauses in a rudimentary garbage collector.

Real-time operation can be "bolted on" to a non-real time operating system as a small specialized kernel which has higher priority access to the CPU and its own, separate resource management.