The easiest way to obtain lparallel is with Quicklisp.
This will download, compile, and load lparallel along with its dependency bordeaux-threads. Alternatively, it may be downloaded manually from the following links:
lparallel should run on any Common Lisp implementation supported by bordeaux-threads. The following implementations successfully pass the lparallel test suite:
To run the test suite,
(ql:quickload :lparallel-test) (lparallel-test:execute)
To run benchmarks,
(ql:quickload :lparallel-bench) (lparallel-bench:execute N)
where N is the number of processors/cores.