[NARKOZ]

For your rails apps you can use 'wysihtml5-rails' gem.

https://github.com/narkoz/wysihtml5-rails

Author plans to update it to use wysihtml as a drop-in replacement.

[tanelj]

Actually there is a new gem for Rails called "wysihtml-rails" (https://github.com/Voog/wysihtml-rails) that is synced with this library.