WebODF

Found this in a mozilla forum.

http://forums.mozillazine.org/viewtopic.php?f=27&t=313496&start=0#

Another implementation under MIT license can be found here:

http://www.codeproject.com/KB/scripting/Javascript_binaryenc.aspx

 //listener for the converted data

      var listener =

      {

         onDataAvailable : function(request, context, inputStream, offset, count)

         {

            //write the data

                 var output = Components.classes["@mozilla.org/network/file-output-stream;1"].createInstance(Components.interfaces.nsIFileOutputStream);

                                //outputFile is a file which will contain the gunzipped data

            if(!outputFile.exists())

                     output.init(outputFile, 0x02 | 0x08, 0644, 0);

            else

                     output.init(outputFile, 0x02 | 0x10, 0644, 0);

                  var scriptable = Components.classes["@mozilla.org/scriptableinputstream;1"].createInstance(Components.interfaces.nsIScriptableInputStream);

               scriptable.init(inputStream);

            var data = scriptable.read(inputStream.available());

            output.write(data, data.length);

            output.close();

         },

         onStartRequest : function(request, context)   

         {

         },

         onStopRequest : function(request, context)

         {

         }

      };

      //fake uri needed to create a channel

      var uri = Components.classes["@mozilla.org/network/simple-uri;1"].createInstance(Components.interfaces.nsIURI);

      uri.scheme = "http://gunzip";

      //fake channel needed to create a request

      var chan = Components.classes["@mozilla.org/network/input-stream-channel;1"].createInstance(Components.interfaces.nsIInputStreamChannel);

      chan.setURI(uri);

      chan.contentLength = decrypted.length;

      chan.contentType = "gzip";

      chan.contentStream = null;

      var request = chan.QueryInterface(Components.interfaces.nsIRequest);

            // Attempt to gunzip

      var conv = Components.classes["@mozilla.org/streamconv;1?from=gzip&to=uncompressed"].createInstance(Components.interfaces.nsIStreamConverter);

      conv.asyncConvertData("gzip", "uncompressed", listener, null);

      conv.onStartRequest(request, null);

                //input is an inputstream which contains the gzipped data

      var avail = input.available();

      //really do the conversion

      conv.onDataAvailable(request, null, input, 0, avail);

      var status = {};

      conv.onStopRequest(request, null, status);

      input.close();