Isn't .jar a Java archive (ie. a mobile phone game or utility) ? Try opening one of them with WinRAR or 7-Zip. If there's something that looks like HTML code you should be able to convert it somehow...
If you can't open any, there may be some form of DRM applied to them, I'm not sure. This format isn't very common. It's probably some relic from the pre-Palm and "PDA" days.
Last edited by DSpider; 01-07-2012 at 03:43 PM.