  In this work we explain the implementation of event-driven real-time
interpreters for the Concurrent Constraint Programming (CCP) and
Non-deterministic Timed Concurrent Constraint (NTCC) for- malisms. The CCP
interpreter was tested with a program to find, concurrently, paths in a graph
and it will be used in the future to find musical sequences in the music
improvisation software Omax, developed by the French Acoustics/Music Research
Institute (IRCAM). In the other hand, the NTCC interpreter was tested with a
music improvisation system based on NTCC (CCFOMI), developed by the AVISPA
research group and IRCAM. Additionally, we present GECOL 2, a wrapper for the
Generic Constraints Development Environment (GECODE) to Common LISP, de-
veloped to port the interpreters to Common LISP in the future. We concluded
that using GECODE for the concurrency control avoids the need of having threads
and synchronizing them, leading to a simple and efficient implementation of CCP
and NTCC. We also noticed that the time units in NTCC interpreter do not
represent discrete time units, because when we simulate the NTCC specifications
in the interpreter, the time units have different durations. In the future, we
propose forcing the duration of each time unit to a fix time, that way we would
be able to reason about NTCC time units as we do with discrete time units.
