CBB uses Perl to implement the "calculation engine" and Tcl/Tk to implement the GUI, and emulates the bookkeeping aspects of Quicken, including the ability to import and export Quicken-compatible QIF (Quicken Interchange Format) data files.
I created the now-extremely-obsolete "shell" version, cbbsh, and contributed various code to the Section 2 "engine," including the bulk of the Quicken import/export code. It is no longer supported in any fashion. (Although there's a "txn" script that I've more recently written for those that want to add transactions to the system from the command line...)
Note that CBB uses tab-delimited data files and thus could readily be interfaced to Rand/Hobbs RDB. Building RDB database schema for CBB has unfortunately been on my "to-do list" for quite a while, and hasn't moved towards the "done" side at all.
Be aware that there were some minor Y2K problems in the GUI, that have resulted in an upgrade to version 0.8.1, the "Y2K-compliant" version.
The internal database and back end have been "Y2K Compliant" since 1994; I was involved with the design process and pushed that issue hard back at that time.
There has been fairly little maintenance on CBB in some years, but there is some continuing interest and some continuing users... See Professor Marco Cabral's page on CBB