lparallel is a library for parallel programming in Common Lisp, featuring

a simple model of task submission with receiving queue

constructs for expressing fine-grained parallelism

asynchronous condition handling across thread boundaries

parallel versions of map, reduce, sort, remove, and many others

promises, futures, and delayed evaluation constructs

computation trees for parallelizing interconnected tasks

bounded and unbounded FIFO queues

high and low priority tasks

task killing by category

integrated timeouts