Side by side
Kalai vs Scala.js
Both stand on code transpilers. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan Self-hosted
Choose Kalai if you want to translate supported Clojure code for use in other languages and can work through its command-line tool. Look elsewhere if your code depends on unsupported Clojure constructs or you need a REPL-centered workflow.
Visit Kalai
Free plan APILinuxMac+2
Scala.js brings Scala typing and tooling to JavaScript development, with listed routes to interoperate with JavaScript libraries. Review the 1.22.0 compatibility note if upgrading from 1.21.x.
Visit Scala.jsThe facts
| Kalai | Scala.js | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Not published |
| Runs on | Self-hosted | API, Linux, Mac, Web, Windows |
| Lowest paid plan | Free or on request | Free or on request |
| Plans published | 1 | 1 |
| Maker | Not published | Not published |
| Website | github.com | scala-js.org |
| On code transpilers | #18 of 28 | #14 of 28 |
Kalai: what it does well
- Free and open-source under the Eclipse Public License 2.0.
- Translates Clojure source to target-language source.
- Targets include Rust and Java, with C++ also referenced.
- Maps namespaces, functions, variables, and atoms into target structures.
- README welcomes pull requests and links to contribution guidance.
What to know first
- Supports only a subset of Clojure constructs.
- Rejects top-level forms other than defn and def.
- Requires the Clojure command-line tool to run.
- Gives up REPL and interactive development style.
Scala.js: what it does well
- Compiles Scala applications for browsers, Node.js, and serverless environments.
- Supports JavaScript libraries and APIs.
- Offers four named build tool options.
- Editor support flags typos and type errors.
- Free under Apache License 2.0.
What to know first
- The 1.22.0 release is not entirely source compatible with 1.21.x.
- Tutorials list Scala development tools and Node.js as prerequisites.
Alternatives to Kalai Alternatives to Scala.js The whole list