writeexcel tool for ruby

require 'rubygems'
require 'writeexcel'
workbook = Spreadsheet::WriteExcel.new('ruby.xls')
# Add worksheet(s)
worksheet  = workbook.add_worksheet
worksheet2 = workbook.add_worksheet
# Add and define a format
format = workbook.add_format
format.set_bold
format.set_color('red')
format.set_align('right')
# write a formatted and unformatted string.
worksheet.write(1, 1, 'Hi Excel.', format)  # cell B2
worksheet.write(2, 1, 'Hi Ruby.')           # cell B3
# write a number and formula using A1 notation
worksheet.write('B4', 3.14159)
worksheet.write('B5', '=SIN(B4/4)')
# write to file
workbook.close