Most simulators and FPGA development tools have a VHDL and Verilog editor embedded in them. However, when using these tools, you can select an alternative (external) editor. This way, when you open a file from within the tool, your external editor is opened instead of the embedded editor. At least one EDA vendor admits that the embedded editor they ship is not up to industry standards. To them, the embedded HDL editor is not meant to be heavily used, but rather as a fall-back editor in case you have not configured your own editor yet.
Some of the EDA tools that have an embedded editor are: