Re: What is being used for compression?
The build process uses Google's Closure Compiler in advanced mode.
It's not as simple as running it against PIE_uncompressed.htc though, it needs to be run on just a portion of the file. Easiest thing for you to do is to grab the latest code from GitHub, make your changes to that, and follow the build instructions http://css3pie.com/documentation/buildi ... om-source/
-- the build script handles the compression automatically.
And of course if your changes are generally useful, please submit them back upstream.