use XML::Twig;

my $data;
{
    undef $/;
    $data = <DATA>;
}

my $XML = XML::Twig->new;
$XML->parse($data);
print $XML->root->children_text;

__DATA__
<HIT>
  <FIELD NAME="body">
  <sep />
  Self-Archiving E-mail Messages in
  <key>Outlook</key>
  The following e-mail self-archiving
  <sep />
  create an Archive folder/.pst file. See
  <key>Outlook</key>
  2003 .pst file Management for instruction
  <sep />
  your messages. Select your
  <key>Files</key>
  (This refers to your primary...
  <sep />
  </FIELD>
</HIT>
[download]

  Self-Archiving E-mail Messages in
  Outlook
  The following e-mail self-archiving
  
  create an Archive folder/.pst file. See
  Outlook
  2003 .pst file Management for instruction
  
  your messages. Select your
  Files
  (This refers to your primary...
[download]

I like Twig as well, however I'm on a enterprise system so have to stick with XML::Simple. Any idea how to do it with that module ?

Any idea how to do it with that module ?

Ha ha ha .... install XML::Twig, because Yes, even you can use CPAN :)

Nope.

Perhaps this horribly evil concoction?

use Data::Dumper;

my $data;
{
    undef $/;
    $data = <DATA>;
}

my @text = grep { /^\S/ } map { s/^\s+|\s+$//g; $_ } $data =~ />([^<>]
++)/g;
print Dumper(\@text);

__DATA__
<HIT>
  <FIELD NAME="body">
  <sep />
  Self-Archiving E-mail Messages in
  <key>Outlook</key>
  The following e-mail self-archiving
  <sep />
  create an Archive folder/.pst file. See
  <key>Outlook</key>
  2003 .pst file Management for instruction
  <sep />
  your messages. Select your
  <key>Files</key>
  (This refers to your primary...
  <sep />
  </FIELD>
</HIT>
[download]

So here's a one-liner that does what you want via XML::Parser:

perl -MXML::Parser -e '$p=XML::Parser->new(Handlers=>{Char=>sub{print 
+"$_[1] "}});
   $p->parsefile("filename.xml")'
[download]

If the amount and types of white-space you get from that are not to your liking, you could either complicate the one-liner a little bit (add tr/ \n/ /s in the sub{}), or just pipe the output to another one-liner...

(updated last paragraph to improve the "tr///" suggestion; to clarify, here's a "really tidy" version of the one-liner:

perl -MXML::Parser -e '$p=XML::Parser->new(Handlers=>
  {Char=>sub{($_=$_[1])=~tr/ \n/ /s; s/^ +$//; print}});
  $p->parsefile("filename.xml"); print "\n"'
[download]

    #!/usr/local/bin/perl
    use strict;
    use warnings;
    
    use HTML::Strip;
   
    main();    
    
    sub main{
       my $xml = qq{
       <HIT>
          <FIELD NAME="body">
             <sep /> 
             Self-Archiving E-mail Messages in 
             <key>Outlook</key> 
             The following e-mail self-archiving 
             <sep /> 
             create an Archive folder/.pst file. See 
             <key>Outlook</key> 
             2003 .pst file Management for instruction 
             <sep /> 
             your messages. Select your 
             <key>Files</key> 
             (This refers to your primary... 
             <sep /> 
          </FIELD>
       </HIT>
};
       my $hs       =  HTML::Strip->new();       
       my $text     =  $hs->parse($xml);
       print $text;
    }
[download]

use strict;
use warnings; no warnings 'uninitialized';

use XML::Rules;

my $parser = XML::Rules->new(
    stripspaces => 7,
    rules => {
        sep => '== ', # same as  sub { return ' ' }
        key => sub {return " <b>$_[1]->{_content}</b> "},
        FIELD => 'content by NAME',
        HIT => 'pass',
    },
);

my $data = $parser->parse(\*DATA);

use Data::Dumper;
print Dumper($data);


__DATA__
<HIT>
  <FIELD NAME="body">
  <sep />
  Self-Archiving E-mail Messages in
  <key>Outlook</key>
  The following e-mail self-archiving
  <sep />
  create an Archive folder/.pst file. See
  <key>Outlook</key>
  2003 .pst file Management for instruction
  <sep />
  your messages. Select your
  <key>Files</key>
  (This refers to your primary...
  <sep />
  </FIELD>
</HIT>
[download]

You'd have to add rules for other tags that appear in your XML! XML::Rules is pure Perl, built on top of XML::Parser so you will have no problem installing it in your home directory or alongside the script.