Hi
I need to know what is the best Real Time Operating System
I need it for industrial apps
and Thanks

My personal preference is QNX, although VXworks is widely used.

I kinda want an open source system

For industrial strength RTOS, open source is not really available. There are RT extensions to Linux, but they are still not hard real time systems. For deterministic real-time systems, there are a limited number of operating systems, and QNX (currently owned by RIM) is probably the pre-eminent one that runs on most every current processor, ranging from x86 to ARM. Take a look at www.qnx.com for more information. FWIW, I have been a QNX user/developer since 1982 and have used it to develop real-time industrial applications since then, some of which are used by the US Navy, major semiconductor manufacturers, and most of the major automotive manufactureres.

I have concluded this result after a long search on web
but i was hopping if there is an open source platform
it seems there was one called lynxos but it became proprietary
any way Thanks