Ruby Toolbox - Explore and compare open source Ruby libraries
The Influencer Marketing Stack - Free resources to launch a killer campaign
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.
Startup Stash - A curated directory of 400 resources & tools for startups
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.
Makerbook - A directory of the best free resources for creatives