polynote (GitHub Repo)
Polynote is a notebook environment that supports multiple languages. It currently supports Scala, Python, SQL, and Vega. It features auto-complete, parameter hints, a WYSIWYG editor for composing text cells, and runtime insight. Runtime insight includes features such as showing you what the kernel is doing at any time, a symbol table that shows variables and functions you have defined, and an editor that highlights failures and runtime exceptions.
RxDB (GitHub Repo)
RxDB, or Reactive Database, is a NoSQL-database for JavaScript Applications. It features multi-platform support, reactive data-handling, data encryption, import/export of the database-state, full TypeScript support, and more. It is useful for UI-based apps that always display the realtime state to the user.