This website is incredibly confusing and hand-wavy, but from what I've read in the past about Pika, I believe (though I had trouble finding this clearly stated)

This website is incredibly confusing and hand-wavy, but from what I've read in the past about Pika, I believe (though I had trouble finding this clearly stated) its key feature is automatic conversion of third-party JavaScript modules to the ES6 (here referred to as ESM) module syntax. For those who aren't familiar, JavaScript has two distinct module syntaxes (and several variations on those). Nodejs brought its own when it came on the scene, and then later browsers standardized on a new one for the web. The two are incompatible in some pretty nasty ways (the former is a runtime function, the latter is fully static). So standard practice is to use a bundler like Webpack or Browserify to concatenate your code and all its dependencies into a single JS file (with modules being properly scoped, artificially, through functions scopes and other tricks) for use in web browsers. Basically, this allows browsers to avoid dealing with however all your modules may import each other; you can even mix both syntaxes in one project. The browser just sees one big file. The problem is, a) this makes it virtually impossible to use any dependencies from NPM on the front-end without a bundler, which means a minimum required amount of configuration and tooling, and b) you lose out on some potential caching benefits because files that may not change much can't be distinguished. So why doesn't everyone just use the new modules syntax so that code can be loaded in the browser, as separate modules, without bundling? Because if even a single one of your NPM dependencies is still in the other syntax, you're up a creek. It's like the IPv6 problem: until everyone has it, nobody does. So projects like (I think) Pika have cropped up to try and address this. If it really does auto-convert packages to the new modules syntax, that eliminates the biggest reason to use build tooling in a modern JS project. You could theoretically get away with having no build process at all.