VxWorks vs. RTEMS

[Gene Smith]

I know rtems has a posix compatibility layer that can be used. Has 
anyone ever thought about making a similar layer that would map vxWorks 
calls to rtems calls? Or is this even possible in a meaningful way? A 
formal comparison between rtems and vxworks is in a paper by Till Straumann

http://epaper.kek.jp/ica01/papers/WEBI001.pdf

that concludes that their performance is about the same and states that 
they both don't provide memory protection for tasks nor virtual memory. 
Is that still true? (I have seen mention of a virtual memory library for 
vx called vxmem.)

I have an application that uses vxWorks and am considering porting it to 
rtems. I am not sure if this ppc based vxworks application uses memory 
protect or not. Pretty sure it does not use virtual memory.

Comment/question appreciated.

Tks,
-gene