# 31mar24 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, +49 8230 5060