JavaScript is versatile and can be used to create a lot of different software products such as browser extensions, web apps, websites, mobile apps, APIs, desktop apps, 2D games, 3D games, and third-party plugins.
Browser extensions can be created for different web browsers, and some popular extensions, such as 'GMass: Powerful Mail merge for Gmail,' generate millions of dollars in revenue.
Web apps, websites, and micro-SaaS are also profitable software solutions that can be built using JavaScript frameworks such as React and Next.js. These can generate millions of dollars every year.
Native mobile apps, hybrid mobile apps, and progressive web apps (PWA) are also great possibilities that offer a universe of possibilities on their own and have the added advantage of being cheaper to develop than fully native desktop apps.
Desktop apps can also be created with Electron.js, which allows developers to use HTML, CSS, and JavaScript.
Application Programming Interfaces (APIs) can be created and sold on an API marketplace like rapidapi.com for passive income streams.
JavaScript libraries and templates can be sold or given away for free and sold for advanced features or services.
2D and 3D games can be built using HTML5 and WebGL API to create interactive games.
Third-party plugins and add-ons can be created for different marketplaces, such as Slack, Shopify, Wix, and more, where there is less competition than in Google Play or Apple's App Store.
Creating and selling eBooks, online courses, or entering the 'web3 field' can also be lucrative fields for JavaScript developers.