Actually that's coincidentally valid YAML:

$ xlsclients -la | perl -MYAML -MData::Dumper -le '$x = do { local $/;
+ <>}; print Data::Dumper::Dumper( YAML::Load( $x ) )'
$VAR1 = {
          'Window 0x600001' => {
                                 'Command' => 'xemacs',
                                 'Machine' => 'foo',
                                 'Icon Name' => 'xemacs',
                                 'Instance/Class' => 'xemacs/Emacs',
                                 'Name' => 'xemacs'
                               },
          'Window 0xa0000e' => {
                                 'Command' => 'xterm -display :11 -geo
+m +0-25',
                                 'Machine' => 'bar.phydeaux.org',
                                 'Icon Name' => 'fletch@bar:~',
                                 'Instance/Class' => 'xterm/XTerm',
                                 'Name' => 'fletch@bar:~'
                               }
        };
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