1. Komodo IDE
-Based on Mozilla project, Komodo is an award winning IDE from ActiveState.
-Being cross-Platform it runs on Windows, Mac or Linux.
-Komodo Edit or Open Komodo is a free/open-source version of Komodo IDE. It’s a source code editor with the same features of Komodo IDE.
-Open-Source and free IDE from Sun Microsystems.
-Cross-Platform, however the Java interface is not heavily customisable. You will have to create a project everytime you have a single file program.
-Made for heavy Java development.
-Languages supported: C/C++, Python, using plug-ins.
-Maintains a plug-in central.
-A heavy and complicated interface makes it not very ideal for starters but professionals may like it.
-Designed for C# and other .NET languages.
-Cross-Platform, enables developers to quickly write desktop and ASP.NET Web applications in case of Linux. Developers can easily port .NET applications created with Visual Studio to Linux and to maintain a single code base for all platforms.
-Mostly used for KDE/QT development.
-Languages supported: C/C++, Ruby and PHP.
-Uses the GTK2 toolkit with basic features of an integrated development environment.
-Languages supported: C, Java, PHP, HTML, Python, Perl, Pascal etc.
-Cross-Platform and light weight.
-Cross-Platform and extensible.
-Languages supported: C/C++, Python (via plug-in).
-GTK/QT development or widget creation available and supports more than one compiler.
-IDE for C and C++ on GNU/Linux.
-Written for GTK/GNOME and comes with glade/gnome GUI designer/code generator.
-Open-source, cross platform IDE for C/C++.
-Also supports syntax highlighting for other languages.
-GNOME application that is extensible by plug-ins. This adds a huge functionality to a normal editor turning it into IDE.
-Only for Linux.
Source: Penguin Inside