Hi there! My name is Joel K. Pettersson, and I've sometimes made small contributions to various MediaWiki extensions. I know Swedish and English.
I'm mainly associated with the following extensions:
I'm not currently involved in wiki software development, though that could change in the future. For other kinds of things, you can look at my personal website.
My main interests in the world of MediaWiki software are Semantic MediaWiki (and similar extensions), scripting support (where I find PhpTags an interesting option), and generally what can be done with more advanced data storage and querying features.
I think the most commonly used approach of providing extension features only through parser functions limits the flexibility of how those features can be used and combined. Scripting provides a more general and powerful way of handling data, and can potentially be used to pass it between extensions. It also has potential for building upon the functionality of types of extensions in a more generic way.