Iceweasel, a free-as-in-speech version of Firefox

IceWeasel is a version of Firefox created for use in "free" operating systems like Debian (and its derivatives, such as Ubuntu), which eschew any element that can't be freely reused by anyone, for any reason. Iceweasel was developed because Firefox and the Firefox logo are trademarked, and because some of the default Firefox plugins can't be freely redistributed. Iceweasel will be synchronized with the current Firefox release, but without the non-free artwork and plugins.

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