RingCube Technologies, maker of operating system virtualization software that facilitates more portable computing, is offering $211,000 worth of rights and securities, according to a filing with the SEC. Based in Mountain View, Calif., the company is backed by Mohr Davidow Ventures and New Enterprise Associates. It last raised funds in 2007, bringing in $12 million. In 2006, it took in a first round of funding totaling $4 million.