Are there any standards or recommended methods when it comes to developing modules/components in this way?? Ideally I would like these to be easy to plug-in into any framework and later down the line I would like to be able to distribute some if these components to other developers.
No, not that I am aware of anyway. There are some problems which would need to be addressed.
WordPress has a wildly different architecture from drupal. Joomla is also significantly different from both of those. In order to “share” modules or components between these distinct systems would be no trivial task.
First off, many of these systems provide a library of code for generating forms, validating data, building interfaces (menus/lists/etc). To complicate matters they are often tightly coupled to the specific architecture.
Now if you wanted to use a “framework” (in the truest sense of the word) such as Zend you would be limited i what you could reuse. Joomla may allow you to swap it’s controllers with a Zend controller class but it would have to implement the same interface as the Joomla controllers; think adapter pattern.
Drupal and WordPress do not really have a distinct controller architecture but instead consist of a series of modules which are implemented as hooks that get invoked at various points of execution.
Modules are (in Drupal) a folder with specific files in it. The module code itself is implemented as standard functions so using Zend controller is out of the question.
There would be no re-use of the front controller architecture in any of the above as each already provides it’s own implementation or something very similar.
The best you could realistically achieve, is using Zend/CodeIgnitor as a library for sending mail, or working with RESTful service or LDAP, etc.
Drupal for instance, offers it’s own FORM API - which if you overrode with Zend would probably cause mass confusion amongst people who download your module and try and manipulate it using the Drupal builtin FORM API.
While it’s technically possible the practical side of me don’t even bother. If you are seeing a business market in writing a components/module once and having it run in Drupal, Joomla and WordPress, you are in for a big challenge.
The most practical approach to solving this would be to follow GTK+ or similar corss-platform framework that can compile and run under Linux, Mac and Windows. Having a component run under WordPress, Joomla or Drupal is very much the same at least at first glance.
Joomla is far more adherent to MVC design pattern than say Drupal/WordPress so bridging that gap would prove very difficult I’m sure.
You would have an easier time making a module cross-platform in WordPress or Drupal because of their similar architecture.