The key mechanism to enable advanced editing capabilities in multiple development tools is via the Language Server Protocol (LSP), which is implemented in good part by the TethysL system.
As a widely used IDE and available for multiple platforms, Visual Studio Code (VS Code) is currently our primary target for smart editing features for TethysL scripts. You can install the TethysL VS Code extension from within VS Code itself.
More details in the TethysL VS Code extension page.
For basic TethysL syntax highlighting, we have also put together configuration files for: JetBrains IDEs, TextMate, Vim, Emacs, Bat, Sublime. We may be enabling language server support for these editors in the future.
Initial TethysL development included a web-based editor, now deprecated.