memory question

This is a bit off-topic, but I haven't found this information in the freebsd
website nor google... and this seems to be the most programmer oriented
mailinglist

If I have 2 or more different programs using the same shared library... The
first program loads the .so at startup and keeps running. My question is
that when the second program starts, does it have to load the .so again, or
the memory used by the shared library will be shared between all the two
programs?

I know that different processes started by the same parent share the .so,
but I wanna know if completely different programs started by different
parents can share the same shared object.

 For example, if perl/DBI started from the shell, and php/mysql started from
apache can share the same libmysqlclient.so in memory.

Thanks for any information and sorry for the offtopic