the language has been designed to be easy to analyze and can be parsed without a symbol table. This makes it much easier to build tools such as debuggers, dependency analyzers, automated documentation extractors, IDE plug-ins, and so on. C and its descendants are notoriously difficult in this regard.

it’s a sequence of regular expression search and replace operations that convert it directly to HTML that are run repeatedly over each others output, plus a bunch more logic written directly in PHP.