Re: Converting a webkit plugin to NPAPI?

You may also want to look into FireBreath (http://www.firebreath.org), which abstracts a lot of the painful bits of NPAPI for you and has workarounds for a lot of known issues on different browsers.  As Stuart mentions that still doesn't get you around the challenges of drawing, which will not be as cut and dried as your WebKit plugin was, but it does simplify the learning curve immensely.

Take a look at http://www.firebreath.org/display/documentation/Event+models+and+drawing+models for more information on what Stuart was talking about as it applies to FireBreath (as well as a link to a blog post Stuart wrote about drawing models on Mac)