Charles River Ventures, a venture capital firm that has invested in web companies like Twitter, but also software and networking companies such as BigBand Networks and Netezza, has raised $320 million in fresh money.

The new fund, CRV’s 14th, shows that some venture capital firms are still able to raise money — even as many of their peers are struggling and being forced to throw in the towel (many are essentially “walking dead,” with their shingle still up on the door, but not making any more investments).

The latest funds bring the firm’s total capital under management to about $2.1 billion, it said in a statement this morning.

In 2006, the firm started something called a QuickStart program, designed to inject rapid, $250,000 chunks into Web 2.0 startups. For this, the firm was credited with recognizing early on that many web companies don’t need much cash to create a working prototype, and that it’s often better for both entrepreneurs and venture capitalists to get companies to that first stage before millions more are invested. Since then, a string of other incubators have popped up around the country that also invest small amounts in teams — often only in the tens of thousands — to get them to the first step.

This latest fund, however, shows that CRV remains set on being a full-fledged venture firm, with serious cash ready on hand. The firm said that its investments have yielded approximately $600 million in returns for the firm’s limited partners over the past two years, referring to three IPOs (BigBand Networks, Netezza and Virtusa) and a number of acquisitions (EqualLogic, bought by Dell; Acopia Networks, bought by F5 Networks; Compete, bought by TNS).

The firm said it will continue to invest in communications, the internet and software, as well as energy.

Other companies in its portfolio include Geni, Great Call, Nantero, RPX, Scribd, SMS Gupshup, Social Media, Vlingo and Yammer.