S oftW are and A lgorithms for R unning on M ulti-core (SWARM) is a portable open-source parallel library of basic primitives for programming multicore processors. SWARM is built on POSIX threads that allows the user to use either the already developed primitives or direct thread primitives. SWARM has constructs for parallelization, restricting control of threads, allocation and deallocation of shared memory, and communication primitives for synchronization, replication and broadcast. Built on these techniques, it contains a higher-level library of multicore-optimized parallel algorithms for list ranking, comparison-based sorting, radix sort, and spanning tree. In addition, SWARM application example codes include efficient implementations for solving combinatorial problems such as minimum spanning tree [3], graph decomposition [8], breadth-first-search [9], tree contraction [10], and maximum parsimony [7].