To me, the best part about sequel is that it works with jruby. I use it as a secret weapon when I need a db automation that runs practically anywhere thanks to JVM (and thanks to Jeremy).
Doesn't both JRuby and CRuby require you to download platform specific executable? Or does JRuby offer a portable standalone executable? If that is the case then I might also switch.
I think you might be slightly more limited in your choice of database drivers compared to MRI Ruby but I believe there’s a JDBC driver that should fill the gap.
Yes, you can use the jdbc adapter made by the JRuby team! https://github.com/jruby/activerecord-jdbc-adapter
Though, in my opinion, the best combo has been Sinatra + Sequel.