Write programming code in several languages, edit and compile fast, with Geany
Geany is a free and efficient programming editor built on top of GTK and supporting a lot of languages.
The most impressive feature of Geany is its being fast. Other than that, its interface is well organized, simple, convenient, and elegant.
Geany will let you work with Java, PHP, C and C#, SQL, Perl, XML, CMake, Fortran and much more, even with templates pre-filled with standard commands.
As you would expect the program offers syntax highlighting, folding of the code to let you focus where you need to focus, auto complete options, etc.