Since June of 2010 I'm been setting up and administering several phpBB3 systems. I have been going through the pains of adding (certified) third-party modifications and board styles, dealing with the site updates, hand-coding changes, etc. I've also been working on setting up a Joomla 1.6 site for a customer (who understands that version's beta/RC) status). Needing to create a customized site template for him (and possible future) customers, as well as needing to also customize modules has had me deep in the code and APIs (Application Program Interface) for phpBB3 3.0.7-PL1, phpBB3 3.0.8, and Joomla betas 14 through RC1.
The agony of what I've been going through with phpBB3 as a implementer and customizer has been tremendous. To modify site features you can dive deep into the PHP code of the site and roll your own software, you can download and install code modifications from the main site - tested for your code version and usually installs... unless you have made previous changes to your site (more on this later), or look around the 'net for other "mods" and take your chance even more. As for the actual installation? You can do it by hand, unzipping files and uploading to your site (and pray the instructions are accurate!), or you can install on you site a special add-on to upload and extract your zip files. That add-on (called "AutoMOD") supposedly tests and installs your new toy. If your lucky it installs without a hitch with every feature ready to go. The next best thing is it installs and you have to do another step (such as upload code that it created and downloaded to you system). The worst thing that can happen is that it finds that it can't install the software because it can't find the sections of your existing code that it needs to change. It uses a fairly unsophisticated search system, so if you've done previous code changes (such as adding another mod) there is a better than even chance that your new feature won't install unless you modify the xml files used by the installer, or go modify the files it complains about to make it happy. And this doesn't even touch upon styles, themes, and imagesets (which for Joomla users are "templates" and "media").
Every page in phpBB3 is often composed of several different files. A common practice is to have "*_header.html", "*_body.html", and "*_footer.html" files. No, these are NOT complete html files but are incomplete segments. I found out the hard way that some HTML editors like to "fix" such files by adding the "missing" sections of the file.
In summary phpBB3 can be a nightmare to customize as far as content and its layout.
Joomla, on the other hand, is a dream as far as customization. Creating new content is often as simple as a word processor style edit. Uploading and installing new content is seamless. Unless badly written, a new add-on won't interfere with, or be interfered with
phpBB3 is great for generating content member content. That's what it's for. But it suffers greatly in the management of appearance and layout - where Joomla shines.
What actually needs to be done is not a bridge, or creating a simple add-on, but create an entirely different project. Changing all the existing phpBB files, templates, etc. into a set of Joomla modules and templates. Now it would just be a Joomla-based site package. Once I gave it some thought these past few months I think I might take it on myself. I'm qualified enough I think to do it (a full systems programmer proficient in over 15 programming languages and variations). Someone earlier in this thread mentioned money. I wonder if that offer still stands?
I'll go it completely on my own unless I get so lucky as to be able to put together a team of people who have been developing in both communities.
Basketcase Software, Inc.