![Developer Edition 42: Wifi Debugging, Win10, Multiprocess Firefox, ReactJS tools, and more - Mozilla Hacks - the Web developer blog Developer Edition 42: Wifi Debugging, Win10, Multiprocess Firefox, ReactJS tools, and more - Mozilla Hacks - the Web developer blog](https://hacks.mozilla.org/files/2015/08/firefox-win10-dark.png)
Developer Edition 42: Wifi Debugging, Win10, Multiprocess Firefox, ReactJS tools, and more - Mozilla Hacks - the Web developer blog
![Developer Edition 42: Wifi Debugging, Win10, Multiprocess Firefox, ReactJS tools, and more - Mozilla Hacks - the Web developer blog Developer Edition 42: Wifi Debugging, Win10, Multiprocess Firefox, ReactJS tools, and more - Mozilla Hacks - the Web developer blog](https://hacks.mozilla.org/files/2015/08/firefox-win10-light.png)
Developer Edition 42: Wifi Debugging, Win10, Multiprocess Firefox, ReactJS tools, and more - Mozilla Hacks - the Web developer blog
![Firefox Application system font changed and cannot changed back after font substitutions has been made in windows 10 | Firefox Support Forum | Mozilla Support Firefox Application system font changed and cannot changed back after font substitutions has been made in windows 10 | Firefox Support Forum | Mozilla Support](https://user-media-prod-cdn.itsre-sumo.mozilla.net/uploads/images/2017-12-21-21-12-17-4d3149.png)