> I would like to pipe the output of a ruby script to a text file. On 
> unix, I can easily type
> mycommand > output.txt

> With ruby, I typed
> ruby mytestscript.rb > output.txt

> The result still prints out to the standard microsoft commandline 
> console output and not to the file output.txt. How can I achieve the 
> output to a text file?

Stdout is redirected in this fashion, but stderr is not. My guess is
your testscript prints to stderr. To redirect both do: 

c:\Temp>ruby t.rb > out 2>&1           

c:\Temp>cat out      
stdout is redirected 
stderr is redirected 

c:\Temp>cat t.rb                       
                                       
STDOUT.puts "stdout is redirected"     
STDERR.puts "stderr is redirected"