# 09jun24 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