WebDicty is a free translator via the Internet in English, Spanish, French, Italian and Catalan.
It includes definitions of the words you translate if you wish, via the most prestigious dictionaries (WordReference, Cambridge, Merriam Webster, Vox, Garzanti, Hachette, Gran Diccionari de la Llengua Catalana, Wahrig...)
The program stays minimized on the taskbar until you push Alt+F10, and then it automatically appears, ready to translate.