jsii allows code in any language to naturally interact with JavaScript classes. It is the technology that enables the AWS Cloud Development Kit to deliver polyglot libraries from a single codebase!
A class library written in TypeScript can be used in projects authored in TypeScript or Javascript (as usual), but also in C# (and other languages from the .NET family), Go, Java, Python, ... More languages will be added in the future!
Investigation: Support multiple languages
There are many tools/libraries that may be able to assist in taking the existing TypeScript and either convert or interpret it for other languages.
Top Contender: aws/jsii