I've been a satisfied user of Geany, a lightweight IDE, these past few months:

  • automatically detects if it should auto-indent (EG after a function definition in Python)
  • got code-folding
  • can highlight #include file and open it (on new tab); does not do this if it's a system file (/usr/include) though
  • got terminal emulator on bottom (though I don't use it)
  • can automatically detect tab width (or so it claims)
  • has a usage finder which shows where a given function is called, even among multiple files
  • got autosave option as a plugin
  • got file browser option as a plugin (although it does not detect filesystem changes, EG when a file is deleted the view is not updated to reveal such a change)
  • when space-indent is chosen, backspacing through such behaves as if they were tabs which enhances navigability