OmegaT - OmegaT is a free open-source translation memory application for professional translators written in Java.
OSOR - OSOR is the Open Source Observatory, a project to provide a framework for developing and executing autonomous observations.
Crowdin - Localize your product in a seamless way
openDesktop.org - The website openDesktop.
POEditor - The translation and localization management platform that's easy to use *and* affordable!
SourceForge - The Complete Open-Source and Business Software Platform.