title: What are the common libraries for C?
body: <p>C++ has STL and Boost and C# has the .net Framework library. Similarly, what are the most common libraries useful to a C programmer? (Other than the C standard library.)</p>
  
  <p>I am looking for most of the capabilities available in the STL: containers (vectors, linked lists, trees, hash table), algorithms (sorting, searching), file IO and strings.</p>
  
  <p>Ideally, the library should be open-source, work on Windows (cross-platform is fine) and is being used actively.</p>