Dev-C++ with wxWidgets designer
wxDev-C++ is an opensource wxWidgets Dialog designer that mimics the Delphi/Borland C++ Builder designer.
Lightweight and easy to use cross-platform C++ IDE
ZinjaI is a lightweight Cross-platform IDE for programming with C/C++, initially aimed to be used in classroom for learning C++, but powerful enough to manage complex projects as ZinjaI itself.
Code::Blocks is an open-source cross-platform IDE (Integrated Development Environment) for C/C++. Designed with flexibility in mind, most of its features are provided by external modules (plugins) making it easily extendable and configurable.
Kile is a feature-rich LaTeX editor
Kile is a LaTeX editor, a TeX shell that simplifies the creation of LaTeX documents.
FBIde is opensource IDE for FreeBasic compiler. Coded in C++ using wxWidgets library to be as portable as possible.
LuaEdit is an IDE/Text Editor/Debugger for the Lua language. Its interface looks like MS Visual Studio .Net� and includes syntax highlighting, code completion, advance breakpoint management, efficient search engines, etc. Client under GPL and server (core debugger) under LGPL.
A RAD GUI Building IDE for wxPython.
EJE is a simple Java editor, perfect to learn Java, without learning a complex development tool. EJE is multi-platform (written in Java), light- weight, user-friendly and have several useful basic features. A good help to start with Java!
Dev-PHP is a well-featured IDE for PHP. Fast and powerful, it is easy to use and has a lot of cool features : class browser, scripts preview, integration with PHP parsers, PHP-GTK library, and Xdebug of course. Dev-PHP-usb slips even into your pocket.
AdaGIDE: GNAT Integrated Development Environment for Windows
NppToR provides R auto-completion and code passing between Notepad++ a
Similar to the windows R gui built in editor, NppToR aims to extend the functionality of code passing to the Notepad++ code editor. In addition to passing to the R gui, NppToR provides optional passing to a PuTTY window for passing to an R instance a remote machine. Easy shortcuts are also provided for easy batch execution, with a monitor for longer running scripts.
SPE is a python IDE with auto indentation&completion,call tips,syntax coloring&highlighting,uml viewer,class explorer,source index,todo list,pycrust shell,file browsers,drag&drop,Blender support.Spe ships with wxGlade,PyChecker and Kiki.
Eclipse Verilog editor is a plugin for the Eclipse IDE. It provides Verilog(IEEE-1364) and VHDL language specific code viewer, contents outline, code assist etc. It helps coding and debugging in hardware development based on Verilog or VHDL.
Pawn Studio is an enhanced IDE for Pawn which supports several features like syntax highlighting, code parsing, auto-indentation, auto-completition, call tips and Doxygen parsing. It also supports RCON for HL1, HL2 and GTA SA:MP and has an FTP explorer.
Collection of Emacs Development Environment Tools
Development of a visual IDE for MinGW is active again thanks to Arthas.
SCREEM is a GNOME website / tag based html editor (ie not WYSIWYG) which aims not only to aid in creating web pages, but also to provide useful site maintainance facilities as well, including automatic link updating, and site upload facilities.
Eclipse based editor for phpBB MOD files
Visual Tcl is a freely-available, high-quality application development environment for UNIX, Windows, Macintosh and AS400 platforms. Visual Tcl is written entirely in Tcl/Tk and generates pure Tcl/Tk code.
JSource is a small Java IDE written in Java using entirely Swing components. It has a light but powerful editor that allows creating, editing, compiling, and running Java files. It also supports syntax highlighting for other programming languages.
A CSV editor plugin for Eclipse which edits CSV files visually and through source text.
XPontus , a free java based, Open Source XML Editor
Kazam is a visual editor and project manager for interactive fiction game creation with Inform, one of the major development tools for this type of games. Kazam is developed with the wxWindows cross-platform GUI package.
The BVRDE is a fully integrated development environment (IDE) for remote cross-platform compiling and debugging of UNIX and LINUX console applications. BVRDE runs on a Windows platform, but compiles and debugs applications on UNIX systems.