Project IDX is described as 'Entirely web-based, integrated development environment. IDX can help you build and deploy applications in various tech stacks without the tedium of setting up development environments for yourself and others on your team' and is a Code Editor in the development category. There are more than 50 alternatives to Project IDX, not only websites but also apps for a variety of platforms, including Mac, Windows, Linux, BSD and Flathub apps. The best Project IDX alternative is Notepad++, which is both free and Open Source. Other great sites and apps similar to Project IDX are Visual Studio Code, Sublime Text, VSCodium and Vim.