As a start, I will create some heap fragmentation tests and see how thing goes. It really sounds scary that WASM doesn’t support virtual memory. I will experiment with different allocators and if I find a good solution, I will let you know. My current issue is that I am use an implicit function for drawing on a mesh and I fear that will be extremely slow on WASM. But again, it is nice that it is easy to globally replace the allocator in VTK