Languages: Fr / En / Cn / Nl / It / ...
Compatibility: Windows 7/Vista/XP/2008 Server/2003 Server
License: Freeware.
Author's description:

QTranslate is a free translator for Windows (Windows 7/Vista/XP/2008 Server/2003 Server). With this small utility, you simply select the text you want to translate and then press hot key (Ctrl+Q to show translation in the popup window or Double Ctrl click to show the translation in the main window). The program also has the ability to speak text (Ctrl+E) and perform a web search (Ctrl+W). Also, you can open the main window and type text manually.

Note! The program translates a text by using online translation services, so you need an Internet connection.

The current version supports the following translate services:

Google Translate (translate.google.com);
Microsoft Translator (microsofttranslator.com);
Promt (http://www.translate.ru);
Babylon (translation.babylon.com);
SDL (http://www.freetranslation.com);
Yahoo! Babel Fish (babelfish.yahoo.com);
Яндекс перевод (translate.yandex.ru).

The program has two modes of translation by mouse selection (click on the program icon in the system tray to turn this mode on):

Show icon (Select text in any program, the program icon will appear near the cursor. Click on the icon, the popup window with the translation of the selected text will appear);
Show translation (Select text in any program and the popup window with the translation of the selected text will appear immediately).

The main features:

Translate text in any application that supports text selection (Google Chrome, Microsoft Word, Microsoft Outlook, Acrobat Reader, Skype, IE and etc.);
Back translation;
Replace the selected text with its translation;
Instant translation;
Spell checking;
Text to speech synthesis;
Word suggestion/autocomplete (Ctrl+Space);
History of translations (Ctrl+H);
Virtual keyboard;
Portable version.

Website : http://www.quest-app.appspot.com/
Download page: http://www.quest-app.appspot.com/download