Ok, yes i think the web/html viewer control probably uses InternetExplorer engine so this build might be Windows specific.

I can make a build which converts to simple text for linux/mac users who just want to view text.

I will look into adding the checkbox, and image support... you say that it uses png format?

Also your virtualbox xp will need the .net framework 2.0 installed. I tested on netbook with winxp and framework 2.0 and it ran fine.