Peter is right to recommend Sinatra. There are typically two types of Sinatra applications. Modular and classical. For your example, I'll create a classical application. It isn't much work to convert it to a modular if you find that style would better fit your needs.
You'll want to install the gem with gem install sinatra
. Create a new directory for your project and two new files as follows:
# app.rb
require 'sinatra'
get '/' do
erb :index
end
# config.ru
require './app'
run Sinatra::Application
Create another directory called views and add this file:
# index.erb
Hello World!
Then type ruby app.rb and viola, you now have a working project on localhost:4567/
.
To serve static files like css and js, just create a public directory. From there, any file will be able to accessed after the root url. So if you created a css folder, its respective url would be: yourdomain.com/css/styles.css
.
So the entire directory would be as folllows:
app/
app.rb
config.ru
public/
css/
js/
images/
views/
index.erb
Between the Sinatra Book and the read me, you should be able to find all the info you need.
To accomplish the templates, you'll need something called Sinatra Partial.
I'm not too familiar LiveReload but it seems like Compass accomplishes the same thing and has great integration with Sinatra. So long as pow is a rack based, you should have no problem using it.
Here is a Sinatra Bootstrap I use for all my projects. It has Compass and Sinatra Partial preconfigured and makes it really easy to deploy with Heroku. It also uses Slim, Coffeescript, Thin (as the server), Twitter Bootstrap and Sass but it shouldn't be too much work to sub that with your respective favorites or remove them all together.