understanding applications and PAE

["Vanco, Don" <don vanco agilysys com>]

While I hate to use this as a support line I've gotten no help from the 2
local lugs I've queried, and know that there's some heavy hitters lurking
here.

I understand that the Linux kernel can (through PAE) provide memory paging
beyond 4GB of physical memory on 32-bit architecture.  What I need to
understand is: what are the requirements on the application side to utilize
this memory?  I'm looking for documentation / links that talk about
applications and PAE.

Case in point: Lotus Notes on OS400 can address huge amount of RAM, but when
it's running on Linux does it need to be compiled in a specific manner, or
with some specific bit of code / API to address more than the architecture
physically supports?

Thanx
Don