Shared libraries

Why do some apps like Chrome and Firefox have tiny main executables and pack everything in a big shared library that contains everything? It's not like there are other users of the library, and at least on some systems executables should perform a bit better (no risk of needing to be relocated on load).

Other big programs do the logical thing and provide a large executable and no shared libraries. I have even seen some that changed the policy from version to version. What I'm asking is why would you put anything that is only used by a single program outside the executable.

>>5
But what ships with Firefox isn't really "libxul". Inside that you have *EVERYTHING*, including all-specific Firefox code. The Firefox user agent string is inside that file.

The only external things used by Firefox are NSS (SSL networking I think) and sqlite3, and whatever common system-wide libraries it uses.

Put it another way, nobody has ever used the xul shared library that ships with Firefox. Doing it would be suicide anyway — it's not supposed to be public.

Now you're going to tell me everybody is eager to use the several–dozen–of–megabytes–big Chrome lib.

>>7
Could be a way to separate some platform specific launch code from the main program logic, or to load other stuff in parallel while you're waiting for the main program.
Neither of these sound really convincing.