I designed tko (https://github.com/knockout/tko https://github.com/knockout/tko) to make it easy to re-use the best parts of Knockout using tree-shaking ES6 imp

I designed tko (https://github.com/knockout/tko https://github.com/knockout/tko) to make it easy to re-use the best parts of Knockout using tree-shaking ES6 imports. When experimenting with substituting a few modules, I've gotten it down to 4.5k gzipped. It's still quite early on (alpha), but already some folks are using it in production. Plus, it's mostly backwards-compatible with Knockout. While it might not be an ideal, usable solution for this problem yet, it's definitely moving in the direction of filling exactly this niche (among others).