Stephen Shankland/CNET

NEW YORK -- Firefox Mobile OS will launch this summer in five countries, Mozilla CEO Gary Kovacs said at the All Things D conference here Monday.

Kovacs, who announced earlier this month that he will step down from his post as CEO, said that the new operating system, which is designed for low-end devices, will launch this summer in Venezuela, Poland, Brazil, Portugal, and Spain.

A spokesman for the non-profit organization reiterated that Mozilla had announced initial launch countries on February 24 when it was showing off the mobile OS at the Mobile World Congress trade show in Spain.

"The initial countries where Firefox OS devices will be available to consumers are Brazil, Colombia, Hungary, Mexico, Montenegro, Poland, Serbia, Spain and Venezuela," he said in an email. "Exact launch timing is decided by and dependent on our partners."

Mozilla's move to target customers outside the U.S. makes sense given that the OS is targeted for lower-end devices. Kovacs acknowledged that the 1.0 version of the OS that lands on these first phones is just a start. He said the company is simply trying to stimulate the market with the Firefox Mobile OS.

Mozilla announced its first partnerships for the new mobile OS at Mobile World Congress earlier this year. Companies like LG and ZTE say they are already on board to create handsets. Carriers have said they'll support it too, including Telefonica in Europe. The head of AT&T's wireless division said in February that it may consider phones running the OS.

But there are still some skeptics in the market. A high-level Samsung Electronics executive told CNET at the MWC show that the company wasn't interested in Firefox.