From Bluefish project:
Bluefish is a powerful editor targeted towards programmers and Web designers, with many options to write websites, scripts and programming code. Bluefish supports many programming and markup languages, and it focuses on editing dynamic and interactive websites. It features a multiple file editor, multiple toolbars, custom menus, image and thumbnail dialogs, open from the Web, CSS dialogs, PHP, HTML, Java, C, and XML support, external program integration (tidy, weblint, make, javac), and lots of wizards. Bluefish runs on most POSIX compatible operating systems including Linux, FreeBSD, MacOS-X, OpenBSD and Solaris, and in addition it runs on Windows.