Based on Yii 1.1, this emerging social networking platform is both flexible and stable. It uses almost all of Yii features.
You deserve your own social network
How does it work?
Communities!
Any person can create a community. Each community is for a specific topic. Communication within the community is about its topic.
Each community acts like a mini social network. Members upload posts with rich text, videos, photos, docs, links, and audio.
Each community has its own gallery, online chat, events and more.
Users join communities that talk about the topics they like.
Topishare has a private messaging – people can talk using their profile or one of their anonymous avatars.
After 9 months of development it went live - Enjoy 
Let me know what you think. Thanks
Yair