Another display technology was the gyricon, developed since 1997 by PARC (Palo Alto Research Center), the Xerox center in Silicon Valley, California. In December 2000, some researchers at PARC founded the company Gyricon Media to market the SmartPaper, an electronic paper based on the gyricon technology. Very briefly (and not so well) explained, the technology was the following one: in between two sheets of flexible plastic, millions of micro-cells contain two-tone (black and white) beads suspended in a clear liquid. Each bead has an electric charge. An external electrical pulse makes the balls rotate and change color, to display, modify, or delete data. In 2004, Gyricon Media began marketing commercial advertising, for example small posters running on batteries. The company ended its activities in 2005, with R&D activities going on at Xerox. Another project has been developed by the company Plastic Logic, this time using both proprietary plastic electronics and the E Ink Technology. As explained on the company’s website in 2009: "Technology for plastic electronics on thin and flexible plastic substrates was developed at Cambridge University’s renowned Cavendish Laboratory in the 1990s. In 2000, Plastic Logic was spun out of Cavendish Laboratory to develop a broad range of products using the plastic electronics technology." 1997 > THE ELECTRONIC BEOWULF PROJECT [Summary] Some digitized versions of treasures from the British Library were freely available online in the late 1990s. One of the first digitized treasures was Beowulf, the earliest known narrative poem in English, and one of the most famous works of Anglo-Saxon poetry. The British Library holds the only known manuscript of Beowulf, dated circa 1000. Brian Lang, chief executive of the library, explained on the website: "The Beowulf manuscript is a unique treasure and imposes on the Library a responsibility to scholars throughout the world. Digital photography offered for the first time the possibility of recording text concealed by early repairs, and a less expensive and safer way of recording readings under special light conditions. (…) This work has not only advanced scholarship; it has also captured the imagination of a wider public, engaging people (through press reports and the availability over computer networks of selected images and text) in the appreciation of one of the primary artefacts of our shared cultural heritage." *** The British Library began offering digitized versions of its treasures, for example Beowulf, the earliest known narrative poem in English and one of the most famous works of Anglo-Saxon poetry.