What is gzip(gfe)?

I see gzip(gfe) in the Use开发者_C百科r Agent in my logs. Here is an example:

05-18 06:44AM 00.897 /NTp9 405 17ms 0cpu_ms 0kb Twitterbot/0.1,gzip(gfe),gzip(gfe)
128.242.241.133 - - [18/May/2010:06:44:00 -0700] "HEAD /NTp9 HTTP/1.1" 405 124 - "Twitterbot/0.1,gzip(gfe),gzip(gfe)"

Does anyone know what this is?

I found this on a link (link defunct, no Wayback)

gzip is as software application for compression and uncompression. This token means, that the server request/response is compressed.

gfe means the Google Front End

You will see this token, if an user translate your website in another language with the Google Translator.

The twitter robot is looking for something on your site. It should say in the GAE logs what resource it is failing on. It may be looking for the robots.txt file or it may be following a link to your site that someone posted (which is likely a bad link).