Opera founder Jon von Tetzchner is leaving the company because of differences with the board.

He wrote in an e-mail to Opera staff that "It has become clear that the board, management and I do not share the same values and we do not have the same opinions on how to keep evolving Opera. As a result I have come to an agreement with the board to end my time at Opera. I feel the board and management is more quarterly focused than me."

He told Reuters that "I'm probably more ambitious and would like to move faster in all areas than the board and the current management do."

This will be his last week.

He is supposed to have ideas for new projects so perhaps he will start a new company.

Von Tetzchner was CEO from 1995 until last year when he became a full-time strategic advisor to the company.

The Opera browser is supposed to have a user base of 200 million and wants to be at 500 million by 2013.