PicoLisp: simple, practical

Picolisp is yet another dialect of the Lisp language, specially written to be radically practical and simple. The key features of PicoLisp are:

  • It is an interpreter only. There is no compiler, not even an intermediate one.
  • As a consequence, Pico Lisp is the most dynamic Lisp in existence today.
  • But it is faster than some compiled Lisps.
  • It uses exactly only one kind of memory structure: the cell. Upon that, everything is constructed.
  • A cell is a cell in the same way it was with the original Lisp, consisting on a head and the rest, that is, a CAR part (which may be either a number, a symbol, or a pointer to another cell), and a CDR part (also a number, symbol or cell).
  • As a consequence, it is incredibly memory efficient, and there is little to none memory fragmentation. Processors cache "loves" our interpreter.
  • It can call C functions directly, no wrapper needed.
  • It includes a database as part of the language itself, very scalable and incredibly fast even for databases of hundreds of gigabytes.
  • It includes an HTTP server.
  • It scales up to many servers and processors.
  • It has the most advanced REPL of any lisp implementation in existence today. You can even develop application just with that and a small editor.
  • You can use the REPL remotely.
  • It is completely free software.
  • It has a nice comunity.
  • It is not a new thing, nor experimental, not something which has not been using in real life. PicoLisp has been used and developed since 1988.

Along these pages, we hope we can convince you to try PicoLisp and see for yourself. If you are coming from Common Lisp, Scheme or Clojure, please have a look at the essay of Alex Burger here.


  • 1 Jan 2010: picoLisp 3.0.1 released! Happy New Year! (go to download section)
  • 13 Nov 2009 : picolisp.org launched.
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