What is Deno.js and how it is different from Node.js

Deno is a javascript runtime same as Node, reached its 1.0 release status on May 13, 2020. Deno was developed by Ryan Dahl, the same person who developed Node. Two Javascript run-times by same person . This raises many questions — What made Ryan to develop another Javascript runtime? What is wrong with Node? Is Deno going to replace Node? Lets find answers to all of these.

Why Deno.js ?

Node was designed in 2009 when Javascript was a much different language. Since then, through standards organisations like ECMA International, the Javascript has been improved continuously. For instance, there was no Promises or async/await when Node was developed. Node’s counterpart to promises was the EventEmitter which has back-pressure issue and later it was mitigated with extra code.

On other hand, out of necessity, Node had to invent concepts which were later taken up by the standards organisations and added to the language differently.

With continuous evolution of Javascript and new additions like TypeScript, building and managing Node project needed extra heavy lifting work. Since Node first release, Javascript and its eco system has changed enough to consider simplifying Node.

In a single line, Node has redesigned to Deno to fix it flaws.