# 05nov25 Software Lab. Alexander Burger

                                                  Perfection is attained
                                   not when there is nothing left to add
                             but when there is nothing left to take away
                                              (Antoine de Saint-Exupery)

      The PicoLisp System
      ===================

      _PI_co Lisp is not _CO_mmon Lisp

PicoLisp can be viewed from two different aspects: As a general purpose
programming language, and a dedicated application server framework.


(1) As a programming language, PicoLisp provides a 1-to-1 mapping of a
clean and powerful Lisp derivate, to a simple and efficient virtual
machine. It supports persistent objects as a first class data type,
resulting in a database system of Entity/Relation classes and a
Prolog-like query language tightly integrated into the system.

The virtual machine was designed to be

   Simple
      The internal data structure should be as simple as possible. Only
      one single data structure is used to build all higher level
      constructs.
   Unlimited
      There are no limits imposed upon the language due to limitations
      of the virtual machine architecture. That is, there is no upper
      bound in symbol name length, number digit counts, or data
      structure and buffer sizes, except for the total memory size of
      the host machine.
   Dynamic
      Behavior should be as dynamic as possible ("run"-time vs.
      "compile"-time). All decisions are delayed till runtime where
      possible. This involves matters like memory management, dynamic
      symbol binding, and late method binding.
   Practical
      PicoLisp is not just a toy of theoretical value. PicoLisp is used
      since 1988 in actual application development, research and
      production.

The language inherits the major advantages of classical Lisp systems
like

   * Dynamic data types and structures
   * Formal equivalence of code and data
   * Functional programming style
   * An interactive environment

PicoLisp is very different from any other Lisp dialect. This is partly
due to the above design principles, and partly due to its long
development history since 1984.

You can download the latest release version at

   https://software-lab.de/pil21.tgz


(2) As an application server framework, PicoLisp provides for

   NoSQL Database Management
      Index trees
      Object local indexes
      Entity/Relation classes
      Pilog (PicoLisp Prolog) queries
      Multi-user synchronization
      DB Garbage collection
      Journaling, Replication
   User Interface
      Browser GUI
      (X)HTML/CSS
      XMLHttpRequest/JavaScript
   Application Server
      Process management
      Process family communication
      XML I/O
      Import/export
      User administration
      Internationalization
      Security
      Object linkage
      Postscript/Printing

PicoLisp is not an IDE. All program development in Software Lab. is done
using the console, bash, vip (vi-style editor) and the Lisp interpreter.

The only type of GUI supported for applications is through a browser via
HTML. This makes the client side completely platform independent. The
GUI is created dynamically. Though it uses JavaScript and XMLHttpRequest
for speed improvements, it is fully functional also without JavaScript
or CSS.

The GUI is deeply integrated with - and generated dynamically from - the
application's data model. Because the application logic runs on the
server, multiple users can view and modify the same database object
without conflicts, everyone seeing changes done by other users on her
screen immediately due to the internal process and database
synchronization.

PicoLisp is free software, and you are welcome to use and redistribute
it under the conditions of the MIT/X11 License (see "COPYING").

It is based on LLVM and compiles and runs on any 64-bit POSIX system.

--------------------------------------------------------------------------------

   Alexander Burger
   Software Lab. / 7fach GmbH
   Bahnhofstr. 24a, D-86462 Langweid
   abu@software-lab.de, http://www.software-lab.de
