When comparing Firefox OS vs Spacemacs, the Slant community recommends Spacemacs for most people. In the question“What are the best file managers for UNIX-like systems?” Spacemacs is ranked 23rd while Firefox OS is ranked 37th. The most important reason people chose Spacemacs is:
Spacemacs is just a well-configured Emacs distribution with community-sourced best in class plugins and layers selected to take the setup pain out of Emacs. Evil mode gives the Vim bindings and modes for fast editing, while Helm makes everything discoverable to make learning to be more productive simple and unintrusive.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Fully open-source
Pro For cheap phones
Mozilla is pushing phones aimed at the most price-sensitive segment of the smartphone market.
Pro Respects your privacy
Firefox OS is not tied to a major advertising platform.
Pro Preconfigured emacs distro
Spacemacs is just a well-configured Emacs distribution with community-sourced best in class plugins and layers selected to take the setup pain out of Emacs. Evil mode gives the Vim bindings and modes for fast editing, while Helm makes everything discoverable to make learning to be more productive simple and unintrusive.
Pro VIM Keybindings with EMACS ecosystem
EMACS ecosystem and language support is best in show. The EMACS is a great IDE that was in search of a good text editor. Spacemacs makes EMACS have a good text editor.
Cons
Con Not officially supported on higher-end phones yet
Con Discontinued by Mozilla
Con Emacs is slow
Emacs is single threaded which means that if you enable all the great features you might be used to from Vim, it will run noticeably slower which can be quite frustrating at times. There are efforts at a concurrent Emacs, but they don't seem to be going anywhere.