Until March, Gina Bianchini was CEO of Ning, the social-networking platform she founded with Marc Andreessen. Published reports indicate that Bianchini left after more than five years to pursue other opportunities. Those include being entrepreneur in residence at Andreessen Horowitz, the venture capital firm that Andreessen co-founded. A successful entrepreneur, she previously founded and served as chief marketing officer at Harmonic Communications. She also directed business development and investor relations at CKS Group and was a financial analyst at Goldman Sachs.