Version 2 of p4wn javascript chess engine released
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

P4wn is a small public domain chess engine that can be embedded in web
pages or run in other javascript environments. It plays well enough to
beat most people, but emphasises playability over perfection, moving
quickly and taking risks when it is ahead.

Version 2 is faster, less buggy, and easier to read than Version 1,
which was released in 2002 as an entry in a 5kB web page contest and
whose extremely compact code baffled would-be contributors. The new
version is well over 5k, but still smallish with no external
dependencies.

Tar and zip files can be downloaded from
https://sourceforge.net/projects/p4wn/files/ while the git tree is
obtainable via https://github.com/douglasbagnall/p4wn or
git://p4wn.git.sourceforge.net/gitroot/p4wn/p4wn


New and better in version 2:
============================

* Everything has been rewritten for clarity and modularity, and to
  avoid namespace collisions.

* It is many times faster, and optimised for modern JITing javascript
  engines.

* There are rudimentary frameworks for testing and experimentation.

* Fewer known bugs.

* Git replaces CVS, and the sourceforge repository is mirrored on
  Github so that javascript programmers might know it exists.

* The name “p4wn”, which was originally intended only for the
  sourceforge subdomain, now applies to the program itself, because
  everyone seemed to assume this was always the case.

* There is an easy API for embedding it in web pages
  (`p4wnify(element_or_id)`).

* The engine has no DOM dependencies and can be run in headless
  javascript engines like node.js, gjs, and Seed.

* P4wn 2 has a CC0 dedication, for where “public domain” is
  insufficient.

Not so good changes:
====================

* P4wn 2 no longer supports Netscape 3 or 4 or MSIE 4 or 5. Nor, in
  all likelihood, unknown previously supported old versions of Opera,
  KHTML, and others.

* P4wn 2 is much larger, even when treated with automatic
  minification. While it is still small for a chess engine and a
  javascript application, it has abandoned tininess as a raison
  d’être, and with that much of its fascination for some people.

Contributors.
=============

These people (and others I have forgotten) created p4wn:

* Douglas Bagnall
* Sven Vahar
* Antony Lesuisse
* Ron Winter
* Chris Lear
* Ivan Yelizariev
* Chanibal

Special mention goes to new contributors *Ivan Yelizariev* and
*Chanibal* whose testing found all kinds of dreadful bugs.

Future plans
============

P4wn now follows a release-when-bored strategy. Development follows
interest and stops and starts suddenly. When here have been no commits
for a few weeks, there may be none for several years, and it is time
for a release -- supposing we find the energy to make a tarball. So
while these plans exist, nobody is actually working on them nor has
any enthusiasm to start:

* Use fancier algorithms, like null-move pruning, quiescence search,
  and iterative search (some of which are already there as options).

* Better (multiple, alternative) interfaces: presenting a history tree
  for undone moves instead of a stack, webGL and HTML5 canvas
  interfaces, various machine and net protocols.

* Experiment with a flat typed array memory model.

* Testing and tuning using a Darwinian tournament.

* Work out why some deep search-tree node counting tests fail, and
  stop that happening.

There are no plans for an HTML5 phone app, but of course anybody is
welcome to do that (this is a FAQ).

Further information
===================

The home page: http://p4wn.sf.net

The mailing list (in the order of 2 messages a year):
https://lists.sourceforge.net/lists/listinfo/p4wn-chess

Git (Github and Sourceforge):
https://github.com/douglasbagnall/p4wn
http://p4wn.git.sourceforge.net/git/gitweb.cgi?p=p4wn/p4wn;a=summary
git://github.com/douglasbagnall/p4wn.git
git://p4wn.git.sourceforge.net/gitroot/p4wn/p4wn

Bug reports tend to be filed on Github.