	In all fiction, when a man is faced with alternatives he chooses
	one at the expense of the others.  In the almost unfathomable
	Ts'ui Pen, he chooses - simultaneously - all of them.  He thus
	_creates_ various futures, various times which start others that
	will in turn branch out and bifurcate in other times...
		- Jorge Luis Borges, "The Garden of Forking Paths"

Borges is an experimental library for building web applications in Ruby.
It leverages Ruby's support of closures and continuations to permit
a highly unusual style of development: Borges abandons the traditional
request/response cycle for linear, imperative control flow, bringing
web development much closer to traditional applications programming,
while still supporting common idioms of web usage such as bookmarking and
backtracking.

Borges development has been continued elsewhere.

http://borges.rubyforge.org