Product Hunt - A website that lets users share and discover new products
openDesktop.org - The website openDesktop.
AlternativeTo - AlternativeTo lets you find apps and software for Windows, Mac, Linux, iPhone, iPad, Android, Android Tablets, Web Apps, Online, Windows Tablets and more by recommending alternatives to apps you already know.
OSOR - OSOR is the Open Source Observatory, a project to provide a framework for developing and executing autonomous observations.
Free Software Directory - The Free Software Directory is a project of the Free Software Foundation (FSF) and United Nations...
SourceForge - The Complete Open-Source and Business Software Platform.