Download "A Celebration of Steve's Life" from apple. http://events.apple.com.edgesuite.net/10oiuhfvojb23/event/index.html This script is based on previous WWDC keynote download script: https://gist.github.com/1012426

down_celebrating_steve.rb

#!/usr/bin/env ruby 
require 'open-uri'

if ["--help", "help", "-h"].include?(ARGV[0]) || ARGV.size < 1
  puts "Usage: #{File.basename __FILE__} ( 540p | 540i | 360p | 360i | 360is | 224p )"
  exit 0
end

size_hash = {"540p" => "2540", "540i" => "1840", "360p" => "1240", "360i" => "0640", "360is" => "0440", "224p" => "0240"}
video_size = size_hash[ARGV[0]]
outfilename = "celebrating_steve.ts"
File.unlink outfilename if File.exists? outfilename
if video_size
  baseurl = "http://qthttp.apple.com.edgesuite.net/11ajdjnvkjnd10weoihf23ohfoihqw/"
  outfile = open outfilename, 'w+'
  puts baseurl + video_size + "/prog_index.m3u8"
  listfile = open baseurl + video_size + "/prog_index.m3u8"
  listfile.each_line do |line|
    next if line =~ /^#/
    file = line.strip.split("/").last
    print "Downloading fragment file: #{file}..."
    infile = open baseurl + "/#{video_size}/" + line.strip
    outfile.write infile.read
    infile.close
    puts "Done"
  end
  outfile.close
else
  puts "Wrong option."
  exit 1
end

how can i use this git to download the celebrating video

You need Ruby. Which is included by OSX, or install on your windows or Linux box.
After installation, fire up command and run:

ruby down_celebrating_steve.rb 540p

The Download went fine - very nice code, but how can I play the file?
Windows Media Player & VLC failed.
What can I use for W7 and OSX to play it?

Try kmplayer(free) on Windows, and MplayerX on OS X (available free in Mac App Store).

Or if you have ffmpeg installed, you can use it to remux TS file into an M4V file and play it with QuickTime. Here is the sample command:

ffmpeg -i video.ts -c:a copy -c:v copy video.m4v