A free IDE for C#, VB.NET, & Boo projects on Microsoft's .NET platform
SharpDevelop is the open-source IDE for the .NET platform. Write applications in languages including C#, VB.NET, F#, IronPython and IronRuby, as well as target rich and reach: Windows Forms or WPF, as well as ASP.NET MVC and WCF. It starts from USB drives, supports read-only projects, comes with integrated unit and performance testing tools, Git, NuGet and a lot more features that make you productive as a developer.
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!
Modifies notepad++ into a GTAGS based minimalistic IDE.
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
Second Life script editor.
Alphons van der Heijden, author of LSLEditor, the great off-line editor and debugging tool for scripting in Second Life, has donated his opus magnum to the free and open source community where it can grow and keep pace with the SL platform!
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.
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.
This project provides binary packages for the Ada front end of GNU compiler collection. The project also provides various Ada libraries like the Ada Web Server and Ada aware Integrated Development Environments (gps and vim).
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.
REM is a NetBeans module for ZK application development. It can be used to create ZK web Applications, ZUL and ZScripi documents. It supports ZUL syntax highlighting, auto indent, code folding, code hyperlink navigation and code completion. It supports palette for some components.
Collection of Emacs Development Environment Tools
Development of a visual IDE for MinGW is active again thanks to Arthas.
wxDev-C++ Portable is the portable version of wxDev-C++
wxDev-C++ Portable is the portable version of wxDev-C++ [http://wxdsgn.sourceforge.net/] The portable version has derived from the devcpp-portable.sourceforge.net project, with wx2.9.3, TDM-GCC MinGW 4.6.1 and with wxctb 0.8 for the wxDevcpp extension -V7.4.2 and newer
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.
XPontus , a free java based, Open Source XML Editor