Tau

Difficult one to review really, as it actually produces a decent warm sound, no audible glitches or zipper noise. It is quite useable as a very basic monosynth for warm basses, and it doesn't have any pretentions of being a complicated highly editable synth. I guess it is released as a taster to interested customers for the pro versions of their synths - but to be honest it hasn't made me too interested in trying them out.

The reason why - it says it has an 18dB/Oct resonant filter, and the layout and design is obviously meant to convey the impression it's some sort of 303 clone.

Well it ain't, and the filter isn't very resonant. Personally it sounds like a 24dB/Oct filter to me (and not a very good one either). I use a Juno 106 (which has a pretty weak filter), an Alpha-Juno (which doesn't even have a self-oscillating filter), and an MC202 (which is the dogs b******s if you can't afford a 303 for proper acid lines) - and the Tau won't sound anywhere NEAR any of these synths. It is in no way anything like a 303 - if you want one then shell out for Rebirth. If you want Roland 80s style synth sounds there are numerous freebies out there that do a far better job, and some that you pay very little for that are good synths.
You could even pick up a JenSX or similar for next-to-nothing that will sound better than the Tau.

However, it's free, so I shouldn't knock it - but it irritates me to think that some might shell out for the pro versions thinking they're going to get something capable of 303 sounds. Uh-uh! The GUI (to me) speaks of false marketing and I don't like it (just one of my personal pet-hates). Muon have lost any custom they might have had from me.

However, if you want a free very basic synth (that actually DOES sound analogue and smooth) then d/l it for a try, but it is not a Roland silver box and never wil be.