Mailbox had raised about $5m from internet service provider AOLbacked venture firm Crunchfund and VC peers Charles River Ventures, Kapor Capital and SV Angel.

HubSpot buys two companies: Chime, a Canada-based Google Chrome plug-in for consolidating web app notifications, and PrepWork, a local provider of software creates pre-meeting briefings.

IDG Capital has had a relationship with Memsic going back to its December 2007 when the US-based electromechanical system (MEMS) solutions provider raised $60m in its IPO in a transaction that at the time valued the business at $226m.

Advanced Underwater Surveys, a St Andrews and Dundee universities spin-out, sells 50% interest to DeepOcean UK to form ADUS DeepOcean.

US-based ShareThis acquires app technology developer Socialize and raises $23m in a series C round

Separately, the company is buying Netherlands-based peer Actiepangina.nl.

Google acquires neural net University of Toronto spin-out DNNresearch.