DOM Expressions is a rendering runtime designed for reactive libraries that use fine-grained change detection, such as those based on Observables and Signals. It enables performant DOM rendering by evaluating expressions in isolation to avoid unnecessary re-renders, and is intended for developers building reactive libraries rather than direct use in projects. The project supports multiple rendering APIs, including JSX, Tagged Template Literals, and HyperScript, and is optimized for speed, as demonstrated in the JS Framework Benchmark.