Gross said he intends to resign as of October 14 and will join Microsoft as a vice president in the company's Internet platform and tools division sometime next year.
"It was purely a case of having an opportunity to work at the biggest software company in the world," said Gross. "They are in an exciting battle with Netscape, and it's exciting to be in the forefront of that battle."
Gross, a seven-year Borland veteran, said the decision to leave the company "was among the most difficult career decisions I have had to make."
A Borland representative said Gross was not involved in day-to-day product development, but was instead concentrating on the integration of technologies acquired through Borland's purchase of Open Environment made earlier this year.
His duties will be assumed by Jothy Rosenberg and Jeff Rudy, who are both vice presidents of research and development, a company representative said.
Gross's departure brings to three the number of high-ranking executives to leave Borland since July. Borland announced the departure of chief financial officer David Mullin in August, and the resignation of CEO Gary Wetsel in July. Long-time Borland chief Philippe Kahn quit the company last year.
Today the company has named Whitney G. Lynn acting president and CEO, replacing William F. Miller, who filled the role temporarily following Wetsel's departure. Miller will return to his original role as chairman of the board.
Borland said Lynn will remain acting CEO until a permanent chief executive is found.
Wetsel resigned July 2 shortly after Borland told Wall Street analysts to expect significant losses at the company. On July 24, Borland reported $34.5 million in revenues for the quarter ending June 30, compared to $53.8 million for the same quarter a year earlier.
After a series of rocky quarters last year, Borland was supposed to be executing a turnaround strategy this year built on a renewed focus on the development tools arena, its original market, and specifically on a successful launch of its Delphi tool. But while widely praised, Delphi has had a hard time battling Microsoft's Visual Basic and Powersoft's PowerBuilder.