Mozilla has officially decided that the next major version of Firefox will require at least Mac OS X 10.5 when running on Apple computers.

"We believe a Mac OS X 10.5 minimum will allow us to provide the best experience possible to our users," Mozilla Mac programmer Josh Aas said Tuesday in a mailing list announcement. Firefox is built on a browser engine called Gecko, and the upcoming version 1.9.3 will have technology for Mac OS X 10.4 and before removed, he said.

The recently released Firefox 3.6 works on Mac OS X 10.4, aka Tiger. Mozilla will support it for some months after the browser's replacement version is issued, which means 10.4 support should continue into 2011.

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