Judy - General purpose dynamic array

Judy is a general purpose dynamic array implemented as a C callable library. Judy's speed and memory usage are typically better than other data storage models and improves with very large data sets. Judy's key benefits are scalability, high performance, and memory efficiency. A Judy array is extensible and can scale up to a very large number of elements, bounded only by machine memory. Since Judy is designed as an unbounded array, the size of a Judy array is not pre-allocated but grows and shrinks dynamically with the array population.

Judy can replace many common data structures, such as arrays, sparse arrays, hash tables, B-trees, binary trees, linear lists, skiplists, other sort and search algorithms, and counting functions.