The Stand-Alone RTLinux is an independent implementation of the real time operative system RTLinux. RTLinux is distributed in a package including kernel patch, for several kernel versions, and chargeable modules. The Stand-Alone has his own boot code for that it doesn´t depend on the Linux kernel for its own funcionality. The RTLinux independation provides us certain advantages and disadvantages:\\

\begin{itemize}
\item We have a RTOS with the same funcionality that RTLinux but reducing considerably the OS memory overhead. The most reduced compilation of Linux for x86 architecutre is about 200Kb, In Stand-Alone implementation is only about 25Kb. A too high price in space to use only certain Linux funcionalities.
 
\item RTLinux portability to architectures without paging is impossible since the current Linux portings only covers architectures with paging managment.

\item The Stand-Alone RTLinux doesn´t have paging managment what allows us to decrease undesirable effects \footnote{In real time systems} that produce systems with MMU like TLB and page misses.
\item POSIX Standard compliant like RTLinux.
\item Interrupt virtualization system of RTLinux although interesting it can fail with modules that use CLI/STI instructions without using the kernel macros, with certain programs like VMWare or with RING3 programs with IOPL=3 that use CLI/STI instructions.
\end{itemize}


The disadvantages are:\\
\begin{itemize}
\item The communication between Remote System and Host is slow. I've been trying to solve this problem in the Tracer with a new aproach, We will see it later. 
\item You can no longer use Linux Driver. In RTLinux, development of Linux Kernel also is usefull to RTLinux, being able to have drivers with a non specific RTLinux implementation.
\item FIFO interprocess comunication mechanism proviedes a quick and simple communication between the Real Time System and Linux because both reside in the same machine. In Stand-ALone this philosophy changes, although it is possible its implementation, is needed a remote communication protocol among 2 computers to carry it out.
\end{itemize}