Have you ever tried Google Translate? It can be found here http://translate.google.com/.
Its a handy little service from google that will translate just about any language into English and in the reverse. So it has French, German, Irish, Welsh etc. and most importantly it has Latin. Of course it doesn’t have medieval languages but it can give a rough translation of Latin. Most of the time I just want to see how literal a translation is or what a particular word means. For that it is really handy. Give it a try sometime!