I didn’t know Iannix has a new homepage design. Last time I looked (roughly a year ago) it still had the old one. There was also no sign this app is in active development. I might have overlooked something, but that was my impression. Glad to see the last release was 12.11.2011.
"UPIC [Iannix’ previous name] is a computerised musical composition tool, devised by the composer Iannis Xenakis. […] Xenakis used it on his subsequent piece Mycènes Alpha (1978), and it has been used by composers such as Jean-Claude Risset (on Saxatile (1992)), Takehito Shimazu (Illusions in Desolate Fields (1994)), Aphex Twin, Mari King , and Curtis Roads."
Watch the demos, IanniX is really cool.