Converts text formatted with an exceedingly simple markup language into valid HTML (iron clad guarantee!) - perfect for comments on your blog. Textile isn’t good for this because not only does it do too much (do commenters really need subscript?), but it can also output invalid HTML (try a <b> tag over multiple lines…). Whitelisting HTML is another option, but you still need some sort of parsing if you want syntax highlighting.

Integrates with CodeRay for sexy syntax highlighting.

comment = <<-EOS
"Ego Link":http://rhnh.net
Wow, this post is awesome. I'd implement it like this:

--- Ruby
def hello_world
  puts "hello world!"
end
---

--- HTML
<strong>Look, HTML code</strong>
---

---
just some normal code
---
EOS

Lesstile.format_as_html(comment)
Lesstile.format_as_html(comment, :code_formatter => Lesstile::CodeRayFormatter) # Requires coderay
Lesstile.format_as_html(comment, :code_formatter => lambda {|code, lang| "Code in #{lang}: #{code}" })

# Also XHTML, for the old schoolers
Lesstile.format_as_xhtml(comment)

Lesstile is used by the enki blogging engine, which has many production deployments. The current release is 1.0.0 and considered stable.

Provides a CodeRay syntax highlighter, but you need to have the gem installed to use it.

gem install coderay

Pick one:

sudo gem install lesstile                          # gem install
git clone git://github.com/xaviershay/lesstile.git # go from source

Tested on 1.8.7-p302, 1.9.2-p0, jruby 1.5.1, and rbx 1.1