Arcadia is a Light Integrated Development Environment (IDE) for the Ruby language written in Ruby using the classic Tcl/Tk GUI toolkit. Some features include an editor with source browsing, syntax highlighting, and code completion, debug support, the ability to work on any platform where Ruby and Tcl-Tk work, a highly extensibility architecture, and support for RAD GUI building.
Arachno Ruby IDE is a development environment with an Emacs-like editor, an integrated very fast GUI debugger, source code browsing, live syntax checking, a local Apache environment for developing/debugging CGIs and integrated FTP, and a GNU diff frontend. The debugger offers an easy way to debug CGI and ERuby Web applications. It runs on Windows 2000 and XP, SuSE Linux 9.1/9.2, and other 2.6 kernel Linux distributions.
Mondrian is a project manager and editor for the Ruby language. It has the familiar look and feel of a modern IDE while remaining dedicated to the uniqueness of the Ruby language and its community. It comes with a dynamic object browser, a full-featured project manager, and does runtime error integration amd syntax highlighting.