inode question: ext4 and ext3

["Mag Gam" <magawake gmail com>]

I was curious if ext4 has dynamic inode allocation. Presently, the
application we run which resides on ext3; we constantly run out of
inodes because each file is about 2KB but there are millions of them.

Also, is ext4 going to be a module or has to be compiled into the kernel?

TIA