They call themeselves timelines or sequencer, the idea behind both is the same: offering a tool for synchronizing and orchestrating programs for music and video through MIDI and OSC messages.
Iannix seems to be an advanced and complex instrument. As its website says:
IanniX is a graphical open-source sequencer, based on Iannis Xenakis works, for digital art. IanniX syncs via Open Sound Control (OSC) events and curves to your real-time environment.
It allows building bidimensional and even tridimensional waveforms that can be used to ‘play’ a virtual instrument, i.e. an OSC or MIDI channel, mapped to whatever you want. You can create these forms manually or you can generate them synthetically through a scripting language.
Duration according to its website is:
a timeline for creative coding. Create live performances, interactive installations, and music visualizations by synchronously composing servos, lighting, and projection
It is a simpler version of Iannix, it hasn’t any scripting language and the interface is more reduced. Though more limited than Iannix, it has a very interesting feature: it can import mp3 tracks so that you can synchronize things with the music, while in Iannix you only have time as a reference.
So I decided to test Duration more carefully. One problem I have though is that Duration only sends OSC messages and no MIDI, so if I want to use it with Resolume 2.4 I need a OSC to MIDI conversion.