This is a simple servlet filter for handling URLs in the form of:
https://some.site/somefile.MYEXTENSION/other/path/stuff
Where somefile.MYEXTENSION could be index.cfm or index.php or some such, e.g.:
https://some.site/index.cfc/other/path/stuff
Basically this lets you do double-wildcards in servlet path matching, similar to a path like ".cfm/ or ".php/", whereas the spec only allows for one.
The default regex used is: "^(/.+\.cf[cm])(/.*)" because this was created to mimic a standard ColdFusion-specific servlet container behavior on any container easily, but you can change the regex by setting the "regex" init-paramter for the RegexPathInfoFilter.