The Level9 interpreter was originally written by Glen Summers. The changes for version 3.0 were made by David Kinder with additional code from Alan Staniforth and Simon Baldwin.

For version 4.0, David Kinder integrated the various bitmap decoders, but all the difficult work was done by Alan Staniforth and Dieter Baron. Alan also supplied the BBC B bitmap changes for version 4.1.

David and Andreas Scherrer worked on version 5.0 to integrate script playback from Andreas' .NET port of the interpreter. Andreas created a test harness to play through all the games, and David and Andreas then worked through the problems this showed up. Andreas also put much effort into painstakingly checking all the graphics in the games, which revealed several issues.

Help, testing and information on the various Level 9 formats was provided by Paul David Doherty. Testing of the fix for Lancelot in version 4.1 was performed by Guido Mureddu.

Stefano Bodrato contributed a change to the Windows port to add an optional dithering effect to the line drawn graphics, to give a representation of how the games would have originally appeared to players connecting an 8-bit computer to a 1980s television.

If you have any comments or queries, contact David Kinder.