SonicXTC have released a new free VST, the Deep Step 606. You can download it at their freebies site here . Check out also their free loop manipulator VST, Beat Twist, and their other nice freebies.
For the computer musicians out there using Windows,, here's some free russian VST synthesizers for you ! The newest addition is the Grey Apparatus version 2, which is a hybrid between an FM synth and a "wavedraw" synth, where you draw the waveform yourself.
Here's something for the Windows VST users: EXD-80, a free drum synth by Third Harmonic Studios . It's a virtual analog drum synthesizer, and good for all kinds of electronic music and more. See more info in this article by Sonic State.
Here's an open-source softsynth with awesome sounds: ZynAddSubFX . It is available for Linux, Windows and MacOS. Here's a sound demo with all sounds coming from ZynAddSubFX. The screenshot is rumored to be from an upcoming GUI rework...