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<h2><span class="mw-headline" id="History">History</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="http://en.wikipedia.org/w/index.php?title=UTF-8&action=edit&section=1" title="Edit section: History">edit</a><span class="mw-editsection-bracket">]</span></span></h2>
<p>By early 1992 the search was on for a good byte-stream encoding of multi-byte character sets. The draft <a href="http://en.wikipedia.org/wiki/Universal_Character_Set" title="Universal Character Set">ISO 10646</a> standard contained a non-required <a href="http://en.wikipedia.org/wiki/Addendum" title="Addendum">annex</a> called <a href="http://en.wikipedia.org/wiki/UTF-1" title="UTF-1">UTF-1</a>
that provided a byte-stream encoding of its 32-bit code points. This
encoding was not satisfactory on performance grounds, but did introduce
the notion that bytes in the range of 0–127 continue representing the
ASCII characters in UTF, thereby providing backward compatibility with
ASCII.</p>
<p>In July 1992, the <a href="http://en.wikipedia.org/wiki/X/Open" title="X/Open">X/Open</a> committee XoJIG was looking for a better encoding. Dave Prosser of <a href="http://en.wikipedia.org/wiki/Unix_System_Laboratories" title="Unix System Laboratories">Unix System Laboratories</a>
submitted a proposal for one that had faster implementation
characteristics and introduced the improvement that 7-bit ASCII
characters would <i>only</i> represent themselves; all multibyte
sequences would include only bytes where the high bit was set. This
original proposal, FSS-UTF (File System Safe UCS Transformation Format),
was similar in concept to UTF-8, but lacked the crucial property of <a href="http://en.wikipedia.org/wiki/Self-synchronizing_code" title="Self-synchronizing code">self-synchronization</a>.<sup id="cite_ref-pikeviacambridge_7-0" class="reference"><a href="#cite_note-pikeviacambridge-7"><span>[</span>7<span>]</span></a></sup><sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span>[</span>8<span>]</span></a></sup></p>
<p>In August 1992, this proposal was circulated by an <a href="http://en.wikipedia.org/wiki/IBM" title="IBM">IBM</a> X/Open representative to interested parties. <a href="http://en.wikipedia.org/wiki/Ken_Thompson" title="Ken Thompson">Ken Thompson</a> of the <a href="http://en.wikipedia.org/wiki/Plan_9_from_Bell_Labs" title="Plan 9 from Bell Labs">Plan 9</a> <a href="http://en.wikipedia.org/wiki/Operating_system" title="Operating system">operating system</a> group at <a href="http://en.wikipedia.org/wiki/Bell_Labs" title="Bell Labs">Bell Labs</a>
then made a small but crucial modification to the encoding, making it
very slightly less bit-efficient than the previous proposal but allowing
it to be <a href="http://en.wikipedia.org/wiki/Self-synchronizing_code" title="Self-synchronizing code">self-synchronizing</a>,
meaning that it was no longer necessary to read from the beginning of
the string to find code point boundaries. Thompson's design was outlined
on September 2, 1992, on a placemat in a New Jersey diner with <a href="http://en.wikipedia.org/wiki/Rob_Pike" title="Rob Pike">Rob Pike</a>. In the following days, Pike and Thompson implemented it and updated <a href="http://en.wikipedia.org/wiki/Plan_9_from_Bell_Labs" title="Plan 9 from Bell Labs">Plan 9</a> to use it throughout, and then communicated their success back to X/Open.<sup id="cite_ref-pikeviacambridge_7-1" class="reference"><a href="#cite_note-pikeviacambridge-7"><span>[</span>7<span>]</span></a></sup></p>
<p>UTF-8 was first officially presented at the <a href="http://en.wikipedia.org/wiki/USENIX" title="USENIX">USENIX</a> conference in <a href="http://en.wikipedia.org/wiki/San_Diego" title="San Diego">San Diego</a>, from January 25 to 29, 1993.</p>
<p>Google reported that in 2008 UTF-8 (misleadingly labelled "Unicode") became the most common encoding for HTML files.<sup id="cite_ref-markdavis_9-0" class="reference"><a href="#cite_note-markdavis-9"><span>[</span>9<span>]</span></a></sup><sup id="cite_ref-davidgoodger_10-0" class="reference"><a href="#cite_note-davidgoodger-10"><span>[</span>10<span>]</span></a></sup></p>
<h2><span class="mw-headline" id="Description">Description</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="http://en.wikipedia.org/w/index.php?title=UTF-8&action=edit&section=2" title="Edit section: Description">edit</a><span class="mw-editsection-bracket">]</span></span></h2>
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