What modern C++ libraries should be in my toolbox?
<p>I've been out of the C++ game for about 10 years and I want to get back in and start on a commercial app.  What libraries are in use these days?</p>

<ul>
<li>User interface (e.g, <a href="http://www.wxwidgets.org/" rel="nofollow">wxWidgets</a>, <a href="http://qt.nokia.com/" rel="nofollow">Qt</a>)</li>
<li>Database</li>
<li>General purpose (e.g. <a href="http://www.boost.org/" rel="nofollow">Boost</a>, <a href="http://loki-lib.sourceforge.net/" rel="nofollow">Loki</a>, STL)</li>
<li>Threading</li>
<li>Testing</li>
<li>Network/sockets</li>
</ul>

<p>I looking to be cross-platform compatible (as much as possible out-of-the-box).</p>

<p>What libraries to do you rely on?  What features do they provide that make them <em>"indispensable"</em>?</p>

<p>See <a href="http://stackoverflow.com/questions/777764/what-modern-c-libraries-should-be-in-my-toolbox/782146#782146">my answer</a> below for a summary.</p>
