Software seems to evolve symbiotically with the human mind – it competes for, and consumes human “attention”, in return producing “utility”. So consider the development tools (IDE's, text-editors, web-browsers, operating systems) that are used to develop Artificial-life software.
It seems to me that these tools are actually self-contained life-forms or virtual worlds themselves, already (though relatively inactive and behaviorally rigid). Then a-life developers, whether realizing it or not, interact with a virtual world of evolving widgets and logic in order to develop another.
If “living components” or “living widgets” can facilitate their development processes themselves, then it is like a purposeful feedback loop.
GUI design is concerned with the ergonomics of human-computer interaction. In a 2D/3D open space virtual world consisting of vector, fractal widgets, there are many possibilities for maximizing its ergonomics toward specific “functional” or “behavioral” goals:
geometry generation and arrangement: position, size, orientation
animated appearance
interpreting hardware input devices / sensors into control events
interpreting control events into widget behavioral reactions
etc...
A general-purpose evolved virtual-world operating system needs to involve interaction with and navigation through files, data, links, source code, executing code, etc..
Possibilities beyond rectangular windows and deterministic event-driven desktop application or web frameworks, include:
2D / 3D scalable vector widget shapes
layout, reaction / behavior – controlled by logic, procedures, or neural networks
continuous, reversible “homoiconic process soup” that links abstract data to its possible spatiotemporal embodiments
snapshot w/ alternate branches that can be explored and reverted
physics (ex: solid collisions preventing overlapping windows)
fractal “metaballs” (scalar polygonization), convex hulls, blobs
meshes that unfold, or deform when touched
physically reactive buttons and sliders
noises and tones
pulsing, oscillating scalars and vectors → motion, size, rotation, color, lights