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IBM patents web transcoding proxies

Web: I link-blogged this, but it’s generated some email already, so it deserves a proper posting.

One thing you quickly learn about IBM where software patents are concerned, is that if IBM Research is making noise about a new software technique, they’ve probably patented it already. A few years ago, IBM was keen on HTTP transcoding — rewriting web content in a proxy, to be more suitable for display and access from less-capable devices, like PDAs and mobile phones.

So I probably should not have been surprised today when I came across USPTO patent 6,886,013, which is an IBM patent on a ‘HTTP caching proxy to filter and control display of data in a web browser’. It was applied for on Sep 11 1997, and finally granted on Apr 26 of this year.

The first claim covers:

  1. A method of controlling presentation on a client of a Web document formatted according to a markup language and supported on a server, the client including a browser and connectable to the server via a computer network, the method comprising the steps of:

    as the Web document is received on the client, parsing the Web document to identify formatting information;

    altering the formatting information to modify at least one display characteristic of the Web document; and

    passing the Web document to the browser for display.

Notice that there’s actually no mention of a HTTP proxy there — in other words, an in-browser rewriting element, such as Greasemonkey or Trixie may be covered by that claim. However, the claim does indicate that the document is passed from the ‘client’ to the ‘browser’, so perhaps having the ‘client’ inside the ‘browser’ evades that.

It appears this really wasn’t original research even when the patent was applied for — there’s probable prior art, even if the patent itself doesn’t cite it. For example, WWW4 in 1995 included Application-Specific Proxy Servers as HTTP Stream Transducers, which discusses ‘transduction’ of the HTTP traffic and gives an example of ‘A “rewriting” OreO (transducer element) that encapsulates each anchor inside the Netscape Blink extension, making anchors easier to spot on monochrome displays’. On top of that, Craig Hughes notes that his ‘senior project at Stanford in 1992 was an implementation of a content-modifying HTTP proxy. It re-worked HTML in http streams to add some markup to enable full navigability through touch screen or voice control, for screen-only kiosks.’

Add this to the ever-growing list of over-broad software patents.

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