CreateWiki currently uses a PHP-based setup file, but ideally we'd get it converted to an extension.json file one of these days. It's not exactly as simple as running that conversion script on the file due to the following reasons:

1. Need to remove the CW_DEBUG_ constants in favor of...a solution not involving constants
   1. This requires changing not just the setup file, but also CreateWiki_backend.php and CreateWiki_body.php
   2. This also requires changing $wgCreateWikiDebug, probably to a boolean
2. Variable substitution -- $wgCreateWikiPath and $wgCreateWikiScript include $IP and $wgScriptPath in their default values, respectively. We'd likely need to move these variables to hubSettings.php or somewhere else...or create a registerExtension-like callback, such as what SpamBlacklist does.
3. Documentation -- currently CreateWiki.php contains a significant amount of actually useful comments (!). Comments in JSON are a pain so we'd need to triple-check that the StaffWiki documentation page contains all the info currently contained in CreateWiki.php and that in our JSON-ful future, the on-wiki documentation page would get updated accordingly every time CW is changed.

So yeah, not exactly a trivial task...