In order to allow cross-platform behaviour, a version of the extension for each of target platforms needs to be included on the CDROM. The files that consitute extensions are located inside directory with name /extensions/data or /extensions/engine. The name of the subdirectory extension resides in contains several parts - name of extension itself, target cpu, target operating system name, and optionally target operating system version. For example, PHP version 4 for windows resides in the directory named /extensions/engine/php4-x86-windows .
Extensions are made available for use by site by special Perl modules that are part of SPWS, so simply putting interpreter for some new language under correct name inside /extensions/engine won't make it available for use by site automatically. Please contact us if you really need some new extension to be added to the set of supported by SPWS. However, if extension is already known by SPWS, one can create an implementation of extension for other platforms not currently supported by SPWS.
The list of extensions to initialize is specified in the /site/config/extlist.conf directory, see of its syntax the introduction to extlist.conf for more information.
Deployment vs Development editions of extension
In order to minimize size taken by extension on CDROM, all parts of implementation that are not necessary for running extension (e.g. documentation, samples supplied by extension's vendor, header files and C libraries) are removed.
In order to be able to comfortably develop using some particular extension (e.g. PHP), a development version of extension should be used. Documentation on each extension suggests where to download development edition of extension.