There’s also a port of Mewa (Meta-level Architecture for Generic Web-Application construction: http://www.adrian-lienhard.ch/files/mewa.pdf) available in Ruby, which runs on-top of Wee. This probably compares to FunFormKit or FormEncode with the exception that it’s all about meta-data and not tied to web-formular at all. A custom formular-editor (with all kinds of relations; single, multiple, single_relationship, multiple_relationship) is below 200 lines of very readable code.
If you don’t like ActiveRecords (the database mapper of RubyOnRails) than just use Og (ObjectGraph) which is very similar to SQLObject (create SQL tables on the fly). It’s part of Nitro, another “major” web-framework for Ruby: