There's always Eclipse, Aptana, Komodo IDEs and other IDEs (NetBeans) to use. Of course you could always use ViM, Vi, Nano, or any text editor (Kate, gedit) or any of the packaged items like BlueFish or Quanta+.
Just google search for software or have a look around Sourceforge for stuff. I know there was a discussion not long ago about Linux development. So search here as well.
Note: Moving to a more appropriate forum.