Stijn Kuipers, also known as Zephod, has released the [BLOK] modular synthesis environment for Windows. Like Cycling '74 Max / MSP, [BLOK] lets you design instruments in any which way, with simple processing blocks / tools.

[BLOK] offers classic synthesizer modules, such as oscillators, filters, envelopes, and effects; a versatile DSP engine capable of additive, subtractive, and FM synthesis; and undo / redo functions, which allow you to undo and fix your work.

Originally created as an educational program to teach audio design principles, [BLOK]'s interface is easy-to-use and self-explanatory. You can connect anything and everything, so long as the blocks you use generate a signal. Because the modular synthesis environment does not hog CPU, you can run it on low-end computers and still create complicated audio setups.

[BLOK] is available in Buzz and VST plug-in formats and requires Visual 2008 Runtime.