Why ULIB?
ULIB is a lightweight library of useful toolkit for C/C++ programming. In contrast to STL, most components of ULIB provide better efficiency and are thereby good alternatives for high-performance applications.

Components
Currently, it includes:

A simple doubly linked list, this can also be used as queue and stack.
An efficient hashing scheme - alignhash, both hash_map and hash_set are provided. C macros & C++ templates. See performance comparison at AlignedHashingPerformance.
Binary trees, such as BST, splay tree, red-black tree and AVL tree.
A list sorting algorithm, this is faster than the qsort() in libc.
A binary search algorithm for text files. It works with line-sorted text files.
A heap and the corresponding sorting algorithm, this is faster than the STL version.
A partition algorithm, this partitions an array into three parts |<=K| K |>= K|, O(1) complexity.
A collection of fast hash functions for various data types.
Primitives for random number generation. Especially useful for designing numerical algorithms.
A collection of bit operation hacks. Especially useful for numerical algorithms and cryptography.
Both a full featured bitmap and a bloom filter.
Several cryptographic algorithms, e.g., AES, RC4, SHA-x, MD5 and etc.
A collection of string utilities, including primitives for parallel file processing.
Timer, shell, combination enumerator and so on.
Supported platforms
64-bit Linux-like OSs are recommended, also available for 32-bit platforms.
Windows with Cygwin.
Performance
A comparison between ULIB aligned hashing and Google sparse/dense hashing can be found at AlignedHashingPerformance.
Acknowledgment
The successful completion of ulib is the result of the cooperation, confidence, and endurance of many people. I greatly appreciate the contributions of those Linux kernel developers and many free software authors.