Sem4r use a lightly modified version of Jekyll to had hard break.

The contents of the directory _post/ is copyright © Sem4r: Everything else is MIT Licensed.

Open file: jekyll-0.5.4/lib/jekyll/site.rb, change the ‘textile’ function to:

def textile(content)
  rc = RedCloth.new(content)
  rc.hard_breaks = false
  rc.to_html
end