Mozilla have updated their wiki with plans to upgrade their codebase; Bugzilla have also said that they will update (with an exemption to keep the project MPL only).
The MPL was previously incompatible with other copyleft licenses like GPL. The new version is compatible (unless exempted) and doesn't require multiple licenses (as currently stands with Firefox and Thunderbird). This will allow Mozilla to incorporate Apache licensed code; but will mean that their software becomes incompatible with GPL2 code."
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