The web is raising the bar for expected application features and reactivity is one common theme. Thick clients are again becoming the norm, further hinting at the form reactivity takes and guiding our choice in how to support it. For these reasons, data binding is a popular feature, yet bound terms are often neither first-class citizens nor higher-order. To further help untangle typical reactive web client code by facilitating compositional reasoning for events and changing data, we created the Flapjax library for JavaScript, which I’ll present in a tutorial fashion. It supports a simple push-driven fragment of functional reactive programming (that can also be thought of as first-class and higher-order extension of push-driven data flow). However, our initial attempt to make the library even more usable by adding supporting syntax was incomplete: gradually typing and side-effects are core mantras to ECMAScript, so experience has shown that we should have incorporated both to make an effective FRP embedding. I’ll discuss the language-level attempt this led me to at Adobe for Flex/ActionScript 3 last summer, and finish with pointers to clear next steps in supporting IDEs and manycores About Bay Area Functional Programmers: BayFP meets monthly with talks on functional programming. Slides and videos from previous talks are available at http://bayfp.org/blog/. The group mailing list is http://groups.google.com/group/bayfp/. Less