Dimdim a company that offers free web conferencing announced that it has raised $6 million in a second round of funding. The concept is similar to WebEx, but free. Dimdim offers all the basic tools that you’d expect from a web meeting service, including a collaborative whiteboard, desktop sharing, audio and video. It doesn’t have too many bells and whistles.

Dimdim can take web meetings out of just the corporate world and make them a broader tool for communication. (My favorite example is still the person in Florida using Dimdim to teach English to Mexican immigrants before they come to the United States.), said the DD Ganguly, CEO, Dimdim.

The company apparently uses free, open-source to create web meetings company and the service has been used by more than 500,000 people in more than 180 companies since it launched in private testing mode in 2007. Dimdim plans to make money by offering a premium service. Advertising in the free version is also a possibility.

The funding comes from existing investors Index Ventures, Nexus India Capital and Draper Richards.