You can use that to replace code by monkey patching
$ cat hi.rb
def method
puts "hi"
end
method
load("hello.rb")
method
$ cat hello.rb
def method
puts "hello"
end
$ ruby hi.rb
hi
hello
Interesting post at http://blog.rkh.im/code-reloading
You can do a hot code load in Ruby using the Kernel#load() call. It won't alter functionality currently on the call stack, but it will change the functionality of everything not on the call stack. With some sympathetic design, you can achieve hot code loading fo high availability in ruby.