LibU is a multiplatform C library which comes under a BSD-style license. This means that you are allowed unlimited redistribution for any purpose of LibU bits (in source or binary form), as long as you retain the copyright notices and the license's disclaimers of warranty:
LibU - Copyright (c) 2005-2012 by KoanLogic srl All rights reserved. ...
That said, LibU includes many interdependent modules for accomplishing several tasks: Memory allocation, Networking and URI parsing (as per RFC 3986), JSON parsing (as per RFC 4627) String manipulation, Flow Control (with bundled debugging and logging functionalities) of C/C++ programs in a very compact way, plus many other Miscellaneous tasks.
Also, it has built-in support for tree-structured Configuration files, or flat configuration files which are supplied through the running process Environment.
HMap s using separate (sorted) chaining or linear probing, linked Lists, an efficient Ring Buffer implementation, Dynamic Arrays, Binary Search Tree and Priority Queues are all provided as building blocks for your custom data structures.
A complete framework for handling authentication via Password like files, data Buffer manipulation, a module for Unit testing of C/C++ programs, and some commodity interfaces for playing safe with the File system, completes the list of functionality.
Also, a portability layer is included which gives replacement for functions that could be missing on some platforms, e.g. strlcat(3), strlcpy(3), gettimeofday(2), etc.; it provides uniform naming to absorb minor interface deltas between different platforms.
Check the Installation instructions and happy hacking !