flor

Flor is a "Ruby workflow engine", if that makes any sense.

Design

Strives to propose a scheming interpreter for long running executions
Is written in Ruby a rather straightforward language with at least two wonderful implementations (MRI and JRuby, which is enterprise-friendly)
Stores everything as JSON (if it breaks it's still readable)
Stores in any database supported by Sequel (the JSON goes in the "content" columns, along with some index columns)
Favours naive/simple implementations over smart ones
All in all should be easy to maintain (engine itself and executions running on top of it)

See doc/.