Translate.Net is free and open source client to many translating services available online (translators, monolingual and bilingual dictionaries). It designed with smart user interface to allow use different services from single place.The program is able to access 17 different translation engines including Google Translate and provide a total of 1,352 pairs of translation between different languages. This small application (680Kb) for Windows required NET Framework 2.0 installed on your computer.
However, Translate.Net requires working connection to internet for processing of queries and retrieving translating results. So if you can't be online when needed or require improved safety of yours translations please use other solutions[source]