2251. PseudoScheme
      PseudoScheme is an implementation of the Scheme (R4RS) programming language in Common Lisp
2252. psgraph
      psgraph is a small package for generating PostScript pictures of directed acyclic graphs written by Joe Bates and mentioned here: Repositories of Lisp Software
2253. ptester
      ptester is a portable version of Franz's tester library
2254. Public Domain
      Works placed in the Public Domain are those to which the copyright has been relinquished
2255. Pupeno
      Hello, I'm Pupeno
2256. purgatory
      A client implementation of the Plan 9 File Protocol
2257. puri
      puri, Portable Universal Resource Identifier, is a library for parsing and representing URIs
2258. Purity Test
      "Have you ever ..." : a Common Lisp Purity Test
2259. PURL
      PURL provides a parser and defines a type for URLs as specified in RFC1738
2260. PVS Specification and Verification System
      The PVS Specification and Verification System is a verification system: that is, a specification language integrated with support tools and a theorem prover

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