Morgan Stanley is the "left lead" underwriter, and is joined by BofA Merrill Lynch as joint book-running manager. Stifel Nicolaus, William Blair, RBC and Montgomery & Co. are co-managers of the offering. Venture Capital investors listed in the S-1 include Polaris Venture Partners, Institutional Venture Partners and Kleiner Perkins Caufield & Byers. Polaris was planning to sell 3.5M shares in the IPO (plus another .5M in the over-allotment option), while IVP and KPCB were not planning to sell any shares in the IPO (or in the over-allotment option).
Here's a link to the Reuters story:
Here's a link to the latest S-1/A registration statement: http://www.sec.gov/Archives/edgar/data/1286139/000104746912007609/a2209713zs-1a.htm
Here's a link to my prior post on LegalZoom: