Camping is a web framework which consistently stays at less than 4kb
of code.  You can probably view the complete source code on a single
page.  But, you know, it's so small that, if you think about it, what
can it really do?

The idea here is to store a complete fledgling web application in a
single file like many small CGIs.  But to organize it as a
Model-View-Controller application like Rails does.  You can then easily
move it to Rails once you've got it going.