For the third year, the Wall Street Journal has published a ranking of the most successful venture capital-backed companies. While Internet start-ups still have a presence, makers of business products took the top three spots, and for the first time, a health care company isn't heading the list.

In fact, Castlight Health Inc., last year's top billing, didn't rank this year at all. Another notable difference from previous years is that no energy sector companies are represented.

Instead, the Texas provider of Internet-based telecom services, Genband Inc., got the highest ranking, followed by Xirrus Inc., a provider of wireless networking equipment which holds second place for the second year in a row. The semi-conductor chip-maker Tabula Inc. came in third. 

The amount of revenue reflected ranges from $26.6 million for UberMedia, Inc. to over $500 million for Genband.

In an interview with Genband Chief Executive Charlie Vogt, the WSJ reported that the company isn't planning to go public anytime soon because it doesn't need to.  "A lot of companies go public because they're trying to raise money, and in our case, we don't need to raise money," he said.

More than 5,900 companies were considered for the ranking. To be eligible they had to be based in the U.S., have received equity financing within the past three years and be valued at less than $1 billion. Each was evaluated based on its fundraising success, growth in value and the strength of their board members.

Thirty-seven out of the 50 ranked companies are in California and four are in New York. The data was compiled by VentureSources, which is owned by News Corp.