- REPL (ammonite)
- build tool (mill)
- JSON serializer(uPickle)
- web framework (cask)
- test framework(uTest)
- http client lib (requests-scala)
- HTML tag lib (scalatags)
- parser(fast parse)
Scala development and tool can be divided into four categories
- Java (OO): wrong idea for many developers. Use Kotlin if you like OO.
- Haskell (pure FP, even HKT): good for fun but not for profit. Use Haskell for pure FP.
- Erlang (Actors): fibers are better. Use Clojure if you like Actors.
- Easy: practical FP, the above tools from Haoyi. Use them if you program in Scala
I'd guess all is done after work. Please support him to make Scala better: https://www.patreon.com/join/lihaoyi