<p>As of April 2019, there's a new proposal <a href="https://area51.stackexchange.com/proposals/121892/operations-research">Operations Research and Analytics</a> on Area 51.</p>

<p><strong>Update May 2019</strong>: the proposal has passed the commitment stage, and soon will be in public beta.</p>

<p><strong>Update April 2020</strong>: <a href="https://or.stackexchange.com/">Operations Research</a> is open and functioning normally.</p>
