query on "plug-in architecture"

[Vipin Rathor]

 HI all,
Can anyone please answer one of the query regarding the following new
feature in MIT latest kerberos release namely krb5-1.5 :
"plug-in architecture, allowing for extension modules to be loaded at
run-time?"

What does the above feature really mean ? Is it a pluggable architecture for
the new mech-glue so that we can plug-in/plug-out various securtiy mechanims
( like kerberos, SPKm etc) , or is it something different?

Thanks in advance
vipin rathor