OmegaT - OmegaT is a free open-source translation memory application for professional translators written in Java.
Weblate - Weblate is a free web-based translation management system.
SDL TRADOS - Computer-Assisted Translation tool, enabling the use of Translation memory.
Pootle - Multiple file formats.
Crowdin - Localize your product in a seamless way
Zanata - Homepage for Zanata translation software