A while back I have developed templates system for GD Star Rating plugin, called T2. It was good, but there are some limitations that made it not so easy to use. New version of the system is called T3 and it uses similar approach but with many new things.
First plugin to use T3 is GD aZon FUSION (currently in beta). Beta 0.7 version to be released next week will use T3. After that, GD Simple Widgets 3.0 will go into development, and will use T3. GD Star Rating 2.0 will also use T3. So, here is what T3 will bring and improve over T2.
Templates will be stored into files (T2 was using database). One of the problems with database approach was problems storing PHP code also and having templates combine HTML and PHP. This time T3 will have templates in files, and each template will be able to have PHP in it. This part is already done for GD aZon FUSION 0.6 and it works very well. Default templates will be stored in a folder, and there will be function and filter to add new templates from any location. In each template there will be some required elements to identify the template.
Special tags will be more powerful than in T2. Each template will allow for arguments to be passed. And there will be a special template for translations. This tag will allow for multi language templates display through default WP translation system.
Editor panel will be also created for editing templates from the control panel, with list of supported tags, similar to one used by T2.
If you have suggestion on what else to add to the system, please leave a comment.