I am pleased to report that as of December 31, 2015 we have been successfully running a segregated witness testnet, called segnet, and have already implemented rudimentary wallets with support.<br>
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For source code, please look at sipa&#39;s github repo:<br>
<a href="https://github.com/sipa/bitcoin/tree/segwit">https://github.com/sipa/bitcoin/tree/segwit</a><br>
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And some example signing code at my repo:<br>
<a href="https://github.com/CodeShark/BitcoinScriptExperiments/blob/master/src/signwitnesstx.cpp">https://github.com/CodeShark/BitcoinScriptExperiments/blob/master/src/signwitnesstx.cpp</a><br>
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Several wallets have already committed to supporting it including mSIGNA, GreenAddress, GreenBits, Blocktrail, and NBitcoin. More wallets are expected to be added to this list soon. If you&#39;re a wallet dev and are interested in developing and testing on segnet please contact me.<br>
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We&#39;re right on schedule and are very excited about the fundamental improvements to bitcoin that segwit will enable.<br>
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Eric<br>
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