Bluefish is a GUI-based text and code editor that runs on "most (maybe all?) POSIX compatible operating systems including Linux, FreeBSD, Ma cOS X, OpenBSD, and Solaris." It has an impressive feature list, and is both lightweight and speedy. It is not currently under heavy development primarily because it is a mature program that already does exactly what it is supposed to do with no fuss or complaint.
Several Linux.com writers use Bluefish daily because we have found it to be an ideal text editor for producing copy that will appear online rather than on paper. It is also an excellent tool for Web programmers, which is the group of users for whom it was originally written.
This brief video gives you an idea of how Bluefish works, how it looks, and what it can do. After watching it, you may want to download and run Bluefish for yourself, which is easy to do if you are a GNU/Linux user, since binaries that work with most distributions are available from the Bluefish download page if Bluefish isn't in your distribution's repositories -- which it probably is.
Ogg Theora (right-click to download)