Their FAQ mentions the Looking Glass Indirect Display Driver (IDD). That is something to look forward to. Looking Glass will work with an iGPU setup once IDD is released (but no 3D acceleration).

What Looking Glass managed to do was get video memory sharing to work between the guest Windows compositor and a client running on the host (with qemu). Unfortunately, it apparently requires an out-of-tree Linux kernel driver that they call kvmfr. You can apparently still share non-video memory without kvmfr, which may hopefully yield adequate performance.

Demo: https://www.youtube.com/watch?v=cg50X9w5llI