The TurckMMCache project which stopped a year ago because its main developer started to work at Zend got restarted by a new team under the name eAccelerator.

eAccelerator 0.9.1 is available for download under the GNU GPL license. It includes many bugfixes and is compatible to PHP5.

ScriptViewer allows to execute PHP applications without the need of a server system.

It includes PHP, a webserver and a browser (IE based).

This could be very useful to easily create local demos of web-applications.

ScriptViewer is freeware.

This nicely large article on opensourcetutorials.com explains the basic concepts of Bayesian inference (as well as the things needed to understand it, such as conditional probability) and how to implement it in PHP.

A very interesting subject since it opens the road to spam filtering, text matching and many other applications. The example of medical diagnosis demonstrated in the article is very impressive.

The extensive list of sources used for the article might be a good starting point for further research in this field.

The second part in this series of articles is more focused on solving the parameter estimation problem for use in the analyse of (web) surveys.

The Oracle Technology Network has a very extensive article by Wez Furlong about the PHP5 Data Object (PDO) abstraction layer.

After a bit of history the author explains why and how to use PDO. Later on advanced functionality like prepared statements and stored procedures is described. Issues like portability and the current development status of PDO are also discussed.

PHP Version Checker is a version checker and code analysis tool which helps to determine the minimum PHP version and modules / extensions required to execute a given PHP script. It also generates a prerequisite checking function to scan for required dependencies. A very handy piece of open source software which allows to state a definitive minimum version requirement for PHP applications and takes away the ubiquitous task of checking the prerequisites of a PHP program.

The Roadsend PHP compiler has been released in version 1.0. It is a commercial implementation of the PHP compiler which generates binaries which are completely independent from a web server or PHP environment.

The benchmarks published on their website are pretty impressive, as John Lim points out.

John Lim has written an interesting article on how to use xdebug for the profiling of PHP code.

xdebug seems to do quite well at profiling PHP code. With the examples provided in the article it is quite easy to setup a little test for your own code in a few minutes. Very useful to do some tuning when you're done with the development.

xdebug is released under the PHP license.

Ilia Alshanetsky, the release manager of PHP 4.3.x has published the slides of his very interesting presentation Accelerating PHP Applications.

In this presentation, which was held at the International PHP Conference 2004, he gives very precious tips & tricks on how to increase the performance of PHP applications tremendously.

While the presentation mostly contains advice on how to increase the efficiency of a PHP installation, some further PHP code optimization tips are available on his blog.

PDO is the database abstraction extension which will be featured in the future PHP version 5.1. Although this release is several months down the road, PDO does already look very promising.

PDO provides a uniform data access interface, sporting advanced features such as prepared statements and bound parameters. PDO drivers are dynamically loadable and may be developed independently from the core, but still accessed using the same API.

A very interesting project, as it might spread wider than the currently available abstraction layers and is likely to be far more performant than those written in PHP.

The PECL_Gen package allows to create PECL-compatible PHP extensions easily.

It reads in configuration options, function prototypes and code fragments
from an XML description file and generates a complete ready-to-compile
PECL extension.

Very useful to transform existing C/C++ libraries into PHP extensions.

OnLamp have published a very interesting article about how to use shared memory within PHP.

The article describes how to use the semaphore and shared memory extensions to have two PHP processes communicate with each other.

Since PHP 4.2.0 the CType extension has been enabled by default. It allows to check a string for characters of a given type in a very fast way, since it uses a native C library.

The following types can be checked:

• alphanumeric characters
• alphabetic characters
• control characters (line feed, tab...)
• numeric characters
• printable/non-printable characters
• uppercase/lowercase characters
• whitespace characters
• characters representing a hexadecimal digit

The CType functions might be a welcome, time saving replacement for regular expressions in many applications.

Sitepoint have a collection of links to very interesting articles on how to run PHP4 and PHP5 in parallel on the same webserver.

Now that the need of switching from PHP4 to PHP5 is approaching as fast as the release of PHP5, these articles might be very helpful.

OpenSharePoint is an open source Microsoft SharePoint clone written in PHP and released under the GNU/GPL license.

The current features include:

• News
• Events (with calendar)
• Tasks (with calendar)
• Document library
• User management

Sadly enough it isn't compatible to Microsoft's SharePoint yet and does only support MySQL as backend.

While the first release candidate of PHP5 has been made available last week, Zend have started publishing a series of articles about the upcoming PHP5.

The series is called PHP5 In Depth and comes up with six articles about topics as different as the rewritten XML support and the new SQLlite, SOAP, HTMLtidy, COM_dotnet and MySQLi extensions.

As the title promises all articles provide in-depth knowledge about the new functionality available in PHP5 and thus are well worth reading. Especially the SQLlite and COM_dotnet extensions are likely to open completely new possibilities for PHP applications.

Roadsend have announced the availability of a beta program for their PHP compiler.

This sofware compiles your PHP application into native machine code which will run without the need for an interpreter. It allows to create stand alone applications, libraries or even compiled web applications which could be served by Apache.

Currently the compiler supports PHP 4.3.4 and the extensions Standard, Mysql, PCRE, XML and POSIX. Although not all functions of these extensions are supported yet.

This all looks very promising, even though it's a commercial product.

APC is the Alternative PHP Cache. It was conceived to provide a free, open, and robust framework for caching and optimizing PHP intermediate code.

Win32 support was finally added in the new 2.0.2 release. Now even PHP apps running on Win32 systems can make use of this powerful bytecode cache.

PECL::perl embeds Perl Interpreter into PHP. It allows to execute Perl files, to evaluate Perl code, to access Perl variables and to instantiate Perl objects.

This could by pretty useful when you need to integrate legacy Perl applications and scripts into a PHP application.

As the last PHP5 beta before release was published a few days ago, the idea of migrating to the new version starts to become more and more realistic.

The folks from the PHP project have published a very useful and extensive documentation on that subject. It includes all important changes and things to take care about when migrating to PHP5.

It looks like the non-backward compatible changes were kept very little and thus make the migration to the new version fairly easy. This was also confirmed by many people developing with PHP, among which John Lim, the developer of ADO DB.

Andi Gutmans - one of the lead developers of PHP - "guesstimates" that PHP5 will be released in a few months, i.e. around May this year.

The most important new features of PHP5 are:

• The new object model (ZendEngine2) which introduces concepts like private/protected members and methods, abstract classes/methods, exceptions, etc.
• New XML support based on libxml2
• SQLlite the ultra-fast and ANSI SQL-92 compatible flat-file database will be bundled
• The new SimpleXML extension, which allows to handle XML files very easily

SafeSQL is a PHP library which allows to generate safe SQL queries by avoiding SQL injection and testing the syntax. MySQL is supported but according to the author, any other ANSI SQL compatible SQL dialect should work as well.

SafeSQL is currently available in version 2.0.1 under the LGPL license.

The ZZ/OSS Installer is a PHP application which allows to build and deploy applications like PEAR-packages using a web-based interface.

Basically it is to web-applications what the InstallShield is to Windows applications. Except that it's open source software released under the LGPL and it's much cooler!

The features include:

• Installation, update and uninstallation of applications and application modules
• Management of dependencies between packages
• Customizable look and feel through CSS
• Plugin Framework to set up SQL databases from SQL dumps for example
• Self-upgrading installer
• Full, minimal and custom setup profiles
• Definition of packages, applications and distributions in XML

The PHP magazine has also published a nice and extensive article about it.

bitflux has reported the publication of a new xdiff extension to the PECL (CVS folder).

This extension is inspired by the diff/merge command line utilities often used in the CVS context on Unix systems and offers quite the same features as PHP functions.

The features include:

• Comparing two strings/files and showing the differences
• Showing the offsets and line numbers where two files or strings differ
• Compare an original file with two independently modified versions of it in order to integrate the changes in a common version

This functionality would be especially nice to compare two versions of a text or to allow for easy merging of two version branches of the same document.

The new extension was announced on the pecl-cvs mailing list and is being discussed there.

Most of the PHP bytecode caching packages available these days are open source ones but the most performant remains Zend's commercial solution. However the open source solution from Turck Software is coming very close to the Zend Performance Suite.

Open Source solutions available:

• TurckMMCache is often claimed to be the most powerful opcode-cache available but works with PHP as module only (i.e. only with Apache)
• ionCube PHP Accelerator is an opcode cache for Unix systems which was elected best bytecode cache in the 2003 Reader's choice of the PHP Magazin. However according to the website this project seems to have had no activity since january 2003.
• Advanced Power Cache is an interesting package for Unix based systems which was placed third in the PHP Magazin reader's choice.

Zend offers a commercial solution called Zend Performance Suite as well as the new Zend/Win enabler which claims to "outperform default PHP on Linux, while eliminating the inherent instability that has existed until today" when running PHP on Windows. The Win enabler is basically just an official variant of the existing FastCGI solution described by John Lim.

John Lim has also published an excellent overview of PHP caches as well as other ways to improve the performance of PHP applications. Some benchmarks are available there too.

More performance enhancement solutions are listed on hotscripts.com

This month's PHP Magazin features the Jedox Worksheet-Server a nifty piece of software which generates PHP applications out of Excel Spreadsheets. Furthermore OpenOffice.org Calc, Star Office Calc and Lotus 123 are also supported.

The very impressive demos include a sales cockpit and a Basel II cockpit.

Multiple backends like LDAP, OLAP, ODBC and SAP are supported.

The pricing list starts at 3495 € for 10 concurrent users.

The Jedox GmbH is a small software company based in Freiburg, Germany.

According to a post in the bitflux blog, Christian Stocker seems quite impressed by PIMP, the PHP5 Imaging Library presented by Pierre-Alain Joye at this year's PHP conference in Frankfurt.

The presentation indeed uncovers a very ambitious project. Some of the features which make PIMP so attractive and distinguish it from GD are:

- Images filters and color corrections
- Scaling and rotation methods
- More than 20 blending methods
- Plugins support (loaders, filters,render)
- Antialiasing for every bitmap drawing method (polygons, ellipses, curves)
- Support of layers and masks
- Vector drawing functions (using cairo)

Having all these possiblities available natively in PHP5 will open amazing perspectives.

MozPHP is an interesting integration of the Mozilla browser and PHP allowing to execute PHP code within Mozilla.

The application is still under heavy development as the project started in last July but it already seems very interesting, especially for cases when you want to present web-applications offline or when you haven't got a web-server.

Here is a pretty nifty PHP syntax exam (found on php|architect).

It appears to be really difficult, as it requires very in-deep knowledge of the PHP syntax and especially data types as well as how they are evaluated.