1. Practical Common Lisp
    "Practical Common Lisp", an introduction to Common Lisp by Peter Seibel, available on the web at http://www.gigamonkeys.com/book/ and also in dead-tree form from Apress
  2. PRBS
    Library of pseudo-random binary sequence generators (LFSR-2 and LFSR-4) and related functions in Common Lisp
  3. pregexp
    Portable Regular Expressions for Scheme and Common Lisp
  4. PREPL
    prepl is a REPL implementation, also known as a Lisp listener
  5. pretend-event-loop
    This is a common lisp library that simulates an event loop
  6. pretty-function
    pretty-function provides an API for making individual functions pprint differently when written to an output stream
  7. Pretzil
    Pretzil is a Z-Machine (interactive fiction) emulator for McCLIM, which makes it a Game
  8. PrevaylerStorage
    The storage technique aimed primarily at object oriented environments, that challenges DBMS technology, making heavy use of RAM
  9. primecount
    Sublinear (in time and space) counting and summing of integer primes using optimized sieving method
  10. princ-ut-interval
    princ-ut-interval prints time durations in human readable format