in reply to
DIfference between LWP and WWW::Mechanize
www::mechanize is an excellent package, but I've never been able to get a version which passed the tests on the Windows or Linux boxes I've used. So I'll have to disagree with the comments that this should be a replacement for LWP::UserAgent. The fact that this package often (but not always) fails tests on certain platforms makes me reticent to require it for an application.
source: Cpan reviews
But, unfortunately I have not tested in non-unix machine.