Licensed as zlib/png, but binaries are currently €16. It looks like the Unreal integration is being funded in part by a grant from Epic Games.<p>Interesting to see an open source project in this traditionally high-end boutique market. I think comparable tools include BodyPaint 3D ($995), Substance Painter ($150+), 3DCoat ($99+), and maybe ZBrush ($895) and Mudbox ($7-10 / month).<p>When I see what textures look like, independent of the model, it's hard to imagine creating them without some kind of painting interface like this.