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.
Open Watcom consists of the famous Watcom C++ and WATFOR compilers -- now open source. Open Watcom is mainly used for developing embedded, DOS, and ncurses software. Open Watcom includes the C/C++/Fortran IDE from Watcom for DOS and a full set of command-line tools for compilation, including the superb Watcom debugger. Open Watcom emits easy-to-understand errors and warnings when things go wrong. Open Watcom generates small statically linked binaries for Linux, Win32, Win16, OS/2, QNX, NetWare, and MS-DOS real and protected mode, among other targets. However, Open Watcom is still only beta-quality on Linux and BSD. The two most serious issues are imperfect C++ template support and an inability to dynamically link with shared libraries built by GCC. Also, Open Watcom is released under the Sybase Open Watcom Public License, which is considered non-free by most Debian Linux developers. NOTE: Open Watcom binaries for Linux are not available anywhere. You must build it yourself. 1.5 has known build issues on Linux; use version 1.4 or the current daily build instead.
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.
X-develop is a multi-language, cross-platform IDE from Omnicore. X-develop targets the .NET platform, the Mono platform, and the Java platform. It offers advanced code analysis, project-wide on-the-fly error checking, refactoring, smart editing, fast code navigation capabilities, seamless version control system integration, and other productivity-boosting features for C#, Java, JavaServer Pages, J#, and Visual Basic.NET.
U++ is a C++ cross-platform rapid application development suite focused on programmers' productivity without sacrificing runtime performance. Based on strictly deterministic design, it provides a viable alternative to garbage-collected platforms, even for business logic oriented problems.