ZynAddSubFX - ZynAddSubFX is an open source software synthesizer for Linux, Mac OS X and Microsoft Windows.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
Surge XT - Open-source subtractive-hybrid synthesizer formerly sold commercially as Vember Audio Surge.
Brevo - Innovative online Email Marketing solution to manage your contacts, create & send your newsletters and track your results. More than 80 000 clients. Best prices and attractive features.
Qsynth - Qsynth is a simple Qt4 application wrapper for the ...
Campaign Monitor - Email marketing software built for designers and their clients to run successful email campaigns.