Some quick answers:
Is it an “After Effects” killer? I spent a lot of time with AE and used to teach classes on it. I tried to integrate everything I love into the UX of TiXL and change everything I hated :) So, it depends on what you want to make. TiXL has pretty good keyframing and compositing, and we’re working steadily on improving it. It can probably do a lot, with the benefit that you never have to “render,” and you can combine keyframe animations with procedural animations. But tracking, precise sync with video files, and typography animations are still much better in AE. So, for “traditional” 2D vector motion design, AE is a clear winner. For particle effects, composition, and audio-reactive work, TiXL can be a strong option.
As other posters pointed out, it sits somewhere between After Effects, Fusion, TouchDesigner, Blender (with nodes), and Resolume.
Windows — yikes: I’m totally with you. Windows is going downhill, not just since Microsoft’s obsession with AI and forcing everybody into their cloud. We’re working on making in running natively on Linux and MacOS. With .NET and ImGui, chances are pretty good. But as another poster pointed out, moving from DX11 to Vulkan will be a tremendous effort. It might be doable, though, because the largest API-specific implementations are bundled into a few low-level components.
Anyways! Thanks for featuring our project. If you’re curious, give it a try and join us on Discord. We’re a friendly community doing this thing together — not for profit, but because we really like motion graphics and good interaction design.