A few notes about Phalanger future

First, I'd like to aplogoize for the lack of new about the Phalanger project recently. I spent some time working as an intern with the F# team in MSR Cambridge and I also had final bachelor exam this autumn. Anyway, this doesn't mean that there isn't anything new and interesting regarding the Phalanger project comming soon - actually (as I believe) the opposite is true! The topics that I'm going to further discuss in this article is our upcomming support for Silverlight platform, the relation between Phalanger and DLR and also our desire to make Phalanger more open to the community, so stay tuned!

Silverlight and PHP

Silverlight [1] was announced by Microsoft this spring - Silverlight is a platform for developing rich web applications, which technically means a plugin for web browsers that can display the rich content including streaming media and can contain program code to controll the application (it is compatible with wide range of browsers and platforms including Mac and thanks to Mono and Moonlight project also Linux). There are two versions of the platform - the first one (1.0) is now in final version and the second (1.1, recently renamed to 2.0) is currently in alpha version.

The 2.0 version has many interesting features, but for developers the most interesting is that it contains a subset of .NET runtime (so we'll have a limited version of .NET running in a browser on any platform that is supported by Silverlight). This enables the developers to use any programming language for .NET to write the rich web application code. These languages include traditional C# and VB, but also recent Microsoft implementations of Python and Ruby. What does that mean for PHP programmers? Since Phalanger is a compiler for .NET and Silverlight supports subset of .NET in a web browser it was relatively easy to modify it for Silverlight (though for the first try the compilation of Phalanger core part reported something like 800 errors :-)), so that it can be used for developing Silverlight applications in PHP, so you'll be able to use PHP for writing rich client-side applications too! The initial version of the source code with these modifications is already available at CodePlex, however I will publish more polished version and some examples & tutorials in a few days.

Phalanger and DLR

Another project that is somehow related to Silverlight is Dynamic Language Runtime (DLR) [2]. This is a library that makes it easier to run dynamic languages on .NET (and is currently primarilly used to power IronPython and IronRuby on Silverlight). Phalanger was started before this library existed, so it doesn't use it currently. This actually means that Phalanger contains implementation of similar functionality as the DLR provides (though it was designed to support only PHP and not dynamic languages in general) and some of the functionality is thus duplicated. It is important to note that DLR isn't tightly integrated with CLR - it is just a C# library (it's even avilable with source code under permissive license), so there wouldn't be technically no need for using it if it didn't make Phalanger development easier, however it has some very appealing features, so we're considering how these could be used in the existing Phalanger implementation.

Phalanger currently has some features and uses a few optimizations that can't be very well expressed on DLR, so it isn't currently possible to port whole Phalanger to DLR (mainly because PHP language has some constructs that are not available in DLR), but since DLR is a library we can use just some parts that for example allow interoperability with other dynamic languages (a nice sample that demonstrates this currently is available as a sample [3]), or for calling methods of .NET objects (Phalanger currently supports this, but we could take advantage of the support in DLR).

PHP on DLR & PHP Community

Because I believe that implementing PHP on DLR has some support in the PHP community I would be very glad if community was involved in this project, either as developers or as advisors (to make sure it's done in a way in which the community needs it). To make sure that we can communicate with the community, Wez Furlong created a mailing list on php.net where these topics can be discussed - you can find it here: http://news.php.net/php.on.dlr. If you have any comments, especially regarding PHP and Phalanger and Silverlight (and in the future DLR) support, or you want to be engaged in discussions about these problems, feel free to join!

References

• [1] Silverlight - Silverlight Platform Homepage
• [2] A Dynamic Language Runtime - Jim Hugunin's Thinking Dynamic
• [3] DLR Console Prototype Silverlight 1.1 Sample