Why behaviour of Tidy online and Windows command is different?

Hi,
 
I am checking the Tidy online (I think, it is written in Perl) and
Windows Tidy command, the output content is different for same input
content.

1) Online Tidy URL: http://infohound.net/tidy/tidy.pl
<http://infohound.net/tidy/tidy.pl>  
Output content of online tidy adding the below meta tag also.
<meta name="generator" content=
"HTML Tidy for Linux/x86 (vers 11 February 2007), see www.w3.org
<http://www.w3.org/> " />

2) Using the below Windows Tidy command.
tidy -f c:\error.txt -m c:\abc.html

Can anyone help me to understand the difference of both Tidy softwares?
 
Thanks,
Srinivas