SmallDevTools - Handy developer tools with a delightful interface
GitSpo - Measure & engage your open-source community
Google Open Source - All of Googles open source projects under a single umbrella
Devo - Devo delivers real-time operational & business value from analytics on streaming and historical data to operations.
whatdevsneed - This is whatdevsneed.
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.