A simple ruby script to 'flip' text using Unicode equivalents. Also see https://gist.github.com/FiXato/4969073 for Mathematical glyph support.

fliptext.rb

#!/usr/bin/env ruby
# encoding: utf-8
# A simple ruby script to 'flip' text using Unicode equivalents
# Based on the javascript code from http://www.revfad.com/flip.html
# TODO: also implement reverse lookup table.
class String
  def each(&block)
    (0...self.size).each do |idx|
      block.call(self[idx,1])
    end
  end
end

table ={
  # Check if I can also implement: øØåÅŒ and other diacritic characters. 
  # Perhaps force unrecognised characters to their ascii equivalent with iconv?
  [0x0E6].pack('U') => [0x1D46].pack('U'), #æ
  [0x0C6].pack('U') => [0x1D02].pack('U'), #Æ
  [0x153].pack('U') => [0x1D14].pack('U'), #œ
  "a" => [0x250].pack('U'),
  "A" => [0x2200].pack('U'),
  "b" => "q",
  "B" => [0x2107].pack('U'), #Could use better replacement (0x3BE)
  "c" => [0x254].pack('U'),
  "C" => [0x2183].pack('U'),
  "d" => "p",
  "D" => [0x25C3].pack('U'), #Could use better replacement; this triangle seems to combine with next char..
  "e" => [0x1DD].pack('U'),
  "E" => [0x18E].pack('U'),
  "f" => [0x25F].pack('U'),
  "F" => [0x2132].pack('U'),
  "g" => [0x183].pack('U'),
  "G" => [0x2141].pack('U'),
  "h" => [0x265].pack('U'),
  'H' => 'H',
  "i" => [0x131].pack('U'),
  'I' => 'I',
  "j" => [0x27E].pack('U'),
  "J" => [0x017F].pack('U'),
  "k" => [0x29E].pack('U'),
  # "l" => [0x283].pack('U'),
  "L" => [0x2142].pack('U'),
  "m" => [0x26F].pack('U'),
  'M' => 'W',
  "n" => "u",
  "N" => [0x1D0E].pack('U'),
  "p" => 'd',
  'q' => 'b',
  "r" => [0x279].pack('U'),
  "R" => [0x1D1A].pack('U'),
  "t" => [0x287].pack('U'),
  "T" => [0x22A5].pack('U'),
  "v" => [0x28C].pack('U'),
  "V" => [0x245].pack('U'),
  'u' => 'n',
  'U' => [0x22C2].pack('U'),
  "w" => [0x28D].pack('U'),
  "y" => [0x28E].pack('U'),
  'Y' => [0x2144].pack('U'),
  "." => [0x2D9].pack('U'),
  "[" => "]",
  "(" => ")",
  "{" => "}",
  "?" => [0x0BF].pack('U'),
  "!" => [0x0A1].pack('U'),
  "'" => ",",
  '"' => [0x201E].pack('U'),
  "<" => ">",
  ">" => "<",
  "_" => [0x203E].pack('U'),
  '&' => [0x214B].pack('U'),
  [0x203F].pack('U') => [0x2040].pack('U'),
  [0x2045].pack('U') => [0x2046].pack('U'),
  [0x2234].pack('U') => [0x2235].pack('U'),
  "\r" => "\n",
}
text = ARGV.join(" ")
revtext = []
text.each do |char|
  if table.has_key?(char)
    revtext << table[char]
    next
  end
  if table.has_key?(char.downcase) #Fallback for lowercase characters.
    revtext << table[char.downcase]
    next
  end
  revtext << char
end
puts revtext.reverse.join('').gsub(")-;","(-;").gsub(")-:","(-:").gsub(");","(;").gsub(");","(;").gsub("(-:",")-:").gsub("(:","):").gsub("#{table["D"]}:","#{table["D"]}-:") #implement more common smiley correction