Open source software manufacturer Mozilla has announced that CEO Gary Kovacs will be stepping down from his role later this year. A search for a successor to Kovacs, who became CEO in 2010, will begin immediately, the firm said.

“I am very proud of our accomplishments as a team,” said Kovacs. “With this solid foundation and a strong team in place, this is the right time for me to announce the transition plan and a vote of confidence in the abilities of the leadership team.”

The firm has been focusing its attentions on the mobile space in recent months. It held a press conference at Mobile World Congress 2013 in February, at which executives of Telecom Italia, Telenor, Telefónica, America Movil and Deutsche Telekom voiced their enthusiasm for the Firefox browser developer’s new HTML5-based smartphone OS.

At the event, Kovacs warned that “the internet should not be controlled by any one or two companies,” and that, “we shouldn’t have one or two companies that approve every bit of content [on smartphones].” He added that Mozilla wants to “level the playing field”.

The software developer also revealed earlier this month it is collaborating with Samsung on a web browser engine called Servo.

With Kovacs departing, Mozilla is making wholesale changes to its workforce. Mitchell Baker, Mozilla CEO until 2008, has returned to the firm to become its executive chair. Jay Sullivan, previously SVP of products, has been appointed COO. Harvey Anderson has been appointed SVP business and legal affair, and Li Gong has been appointed SVP for mobile devices.