- The basic notion: a project, really just a group of files or directory structures. The basic window would allow you to drag files onto a fresh group, and save/load groups to a file list. Opened in a directory with such a file list, the tool would load it automatically.
- "Steps". Not sure where those are defined, but they're individual scripts to run against files or subsets of the files. Might want to toss in file filters to define subsets.
- Step lists. Macro actions consisting of multiple steps. Later with a more sophisticated language (loops and tests, essentially - probably just generic Perl of some kind, munged into a DSL).
That gives us the basic GUI functionality of Okapi, but in a highly configurable shell. This kind of thing could be wrapped around anything.