Cherry Audio is holding their "Year One Celebration" until the 31st of August 2019 and is offering their Voltage Modular Nucleus free during this period. For anyone unfamiliar with this package, it is a collection of 22 modules and 67 presets that offers a great introduction to modular synthesis. Cherry Audio crammed in all the fundamentals of subtractive analog synthesis, so you have oscillators, amplifiers, mixers, filters, and envelope generators, along with an arpeggiator, sequencer, and full suite of useful utility modules and effects modules. 

The package is designed to work with Voltage Modular, which can be run stand-alone or as a VST, AU or AAX plug-in for Windows and MacOS. Voltage Modular is a virtual modular synthesizer aimed at anyone who wants to get the "hands-on" experience of modular synthesis without the huge investment of a real hardware system. For more information about Voltage Modular, check out their frequently asked questions (https://cherryaudio.com/voltage-modular/faq) and don't forget to grab Voltage Modular Nucleus for free while there is still time(https://store.cherryaudio.com/bundles/voltage-modular-nucleus)!