The original 1.0 version was written by mangaman from NukeWorks. It looks as though it was based on the original PHP-Nuke Newsletter module as well as had some concepts from Fancy Newsletter, but not 100% sure on that.
Guardian from http://www.code-authors.com for his constant nagging ( LOL ) for new releases, a few bug fixes, for his Guardian template, for his help in testing, helping to keep an eye on the support forums, and as a contributing editor to the on-line documentation!
Kguske from http://nukeSEO.com for his excellent integration of the FCKEditor into PHP-Nuke by way of his tool nukeWYSIWYG!
Izone from http://www.iranyad.com for his modifications to the base distribution to make the module pages and templates display properly in the Persian language.