Safe user added HTML in Rails

I need to store and display content with user-generated markup, like questions at stackowerfl开发者_Python百科ow, for example. What proper ways for it do you know? Pseudo-tags? Real HTML-filtration? What WYSIWYG editors can deal with it?

Maybe use redcloth or similar with Markitup http://markitup.jaysalvat.com/home/, that does Html, Textile, Wiki Syntax, Markdown, BBcode