title: What are some interesting C/C++ libraries to play around with?
body: <p>I'm looking for a few new libraries and for C and C++. In the past most of the time I "accidently" stumbled across a few - and most of them found good use in projects I worked on.</p>
  
  <p>Libraries should run on Mac OS X and Linux/POSIX and possibly on Windows.</p>
  
  <ul>
  <li><a href="http://www.lua.org/" rel="noreferrer"><strong>Lua</strong></a> - A minimal and fast scripting engine for configuration files and basic application scripting.</li>
  <li><a href="http://code.google.com/p/v8/" rel="noreferrer"><strong>V8</strong></a> - A fast JavaScript by Google engine similar to WebKit's JavaScriptCore.</li>
  <li><a href="http://www.cairographics.org/" rel="noreferrer"><strong>Cairo</strong></a> - A good graphcis library similar to QuickDraw/Quartz on Mac OS X.</li>
  <li><a href="http://zbar.sourceforge.net/" rel="noreferrer"><strong>ZBar</strong></a> - A barcode scanner library, which allows to scan photos/images/video streams for barcodes and return their value.</li>
  <li><a href="http://zlib.net/" rel="noreferrer"><strong>ZLib</strong></a> - A very compact compression library for data streams. Used zziblib and minizip, too.</li>
  <li><a href="http://www.dynaforms.com/" rel="noreferrer"><strong>DynaPDF</strong></a> - A easy-to-use PDF generation library.</li>
  <li><a href="http://www.libusb.org/" rel="noreferrer"><strong>libusb</strong></a> - A universal USB library which allows for portable access to USB devices (I used this to write a basic driver for a custom POS printer).</li>
  <li><a href="http://www.webkit.org/" rel="noreferrer"><strong>WebKit</strong></a> - This is a really nice one if you want to render HTML/Web contents and use it in applications to give your users a "richer" user experience.</li>
  <li><a href="http://qt.nokia.com/" rel="noreferrer"><strong>Qt4</strong></a> - The general purpose framework for all kinds of desktop (and possibly mobile) development. Spending a lot of my time with that - no idea how I could forget that. ;)</li>
  </ul>
  
  <p>This should be marked community wiki. Please update if you have something interesting to add!</p>
  
  <p>Thanks!</p>
  
  <hr>
  
  <h3>Update 1</h3>
  
  <p>I'm not looking for "productivity" libraries like Boost or STL. Instead I'm looking for "interesting new stuff" of random genres - be it graphics libraries, scripting libraries, network or even MOD/MIDI playing libraries. Sorry I didn't make that clear before.</p>