Icecoder is an open-source web development IDE (Integrated Development Environment). It is a powerful web-based code editor that can be used for coding, debugging, and optimizing web applications and websites. Icecoder supports a large range of programming languages such as HTML, CSS, JavaScript, PHP, Ruby, Python, and more. It comes with a range of features like syntax highlighting, code folding, auto-completion, and snippets. Additionally, it offers a powerful search and replace functionality, a file manager, and an integrated terminal. Icecoder also supports version control like Git, allowing users to collaborate on projects and track changes. With its intuitive and modern user interface, Icecoder is a great tool for web developers of all levels.
Discontinued Aptana is still under development on GitHub but the latest version, 3.6.1, was released in October 2014. It lacks Java 8/9 features, as well as more recent JavaScript and HTML 5 features.
Discontinued "Given its age and the number of viable alternatives now available, Codiad is no longer under active maintenance by the core contributors". Https://github.com/Codiad/Codiad/commit/19c9223d70ca0eb164b6891b6e1350c75a62e8f2
It is somewhat similar in that it is an online IDE.