would it be please possible to add css tidy and css validation. css tidy is written in c++ and is under GPL license. the w3c css validator is written in java :-(, can be used as command line and is under W3C SOFTWARE NOTICE AND LICENSE, which is compatible with GPL.
i'm finding many errors in css in epubs and i would like to be able to validate css as in oxygen xml editor.
thanks
http://jigsaw.w3.org/css-validator/DOWNLOAD.html
http://csstidy.sourceforge.net/