ScrollMagic - The jQuery plugin for magical scroll interactions.
LibHunt - LibHunt tracks mentions of software libraries on relevant social networks. Based on that data, you can find the most popular projects and their alternatives.
WOW.js - Animate elements on-scroll to catch attention. Such Magic.
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.
Lax.js - Create beautiful & smooth animations when you scroll
GitSpo - Measure & engage your open-source community