Google Translate - Google's free service instantly translates words, phrases, and web pages between English and over 100 other languages.
Pidgin - Pidgin is an easy to use and free chat client used by millions. Connect to AIM, MSN, Yahoo, and more chat networks all at once.
DeepL Translator - DeepL Translator is a machine translator that currently supports 42 language combinations.
Lingva Translate - Lingva Translate is a language translation application that helps you to translate any language of the world to any language of your choice.
LibreTranslate - LibreTranslate is a free and open-source and self-hostable machine translation server. It also has a public instance designed for personal or infrequent use.
Apertium - To see the whole list of general documentation pages written in English, see documentation in English. Pour ceux qui sont plus à l'aise avec la langue française, une partie des pages anglaises a été traduite.