Jon von Tetzchner, who co-founded Opera Software in 1995, has quit after a serious disagreement with the board over the direction of the company.
The surprise move comes a year after von Tetzchner stepped down from the leadership role at Opera after 15 years.
"We have had a lot of fun during these years, and to say that Jon has created a great company is an understatement", said Lars Boilesen, chief executive of Opera, in a brief statement.
"He believed in, and pushed out, innovation after innovation that we see our competitors constantly struggling with copying, making Opera a first mover in the technological development of web browsers as we know them today. We are aiming at 500 million users by 2013, and we have a very positive flow right now."
However, Boilesen's focus may have been part of the problem. Von Tetzchner was blunt about his reasons for leaving the company in an email to staff, leaked to TechCrunch.
"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," he wrote.
"I feel the board and management is more quarterly focused than me. I have always worked to build the company for the future. I believe the foundation we have is very solid to build further. I believe strongly in Opera as a company, and in all of you working here."
Originally from Iceland, von Tetzchner built the basic code for Opera while at Norwegian telecoms company Telenor.
After acquiring the rights to the software, he and co-founder Geir Ivarsoey built Opera into a respectable smartphone and tablet browser manufacturer with a loyal customer base.
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