Oh, that's good. I saw the demo on their web site and assumed that HTML was the primary/only interface.
> It's also data-file compatible with ledger itself.
And here is a good reason for using plain text files: an RDBMS storage backend would have been unlikely to interoperate with other programs. Note that it couldn't be shared, of course, but the programs would need to agree on a precise database schema where text files, given an extensible syntax, offer more flexibility.