/etc/hosts host file editor for mac osx: gasmask is an app that sits in your system tray and lets you edit the hosts file when you need, and allows for fast hot switching of profiles. Editing the /etc/hosts file on a mac isnt that difficult with commandline or your editor of choice, but it can be a bit of a pain if you have a few sets of hosts that you need access to sometimes, eg for a development environment while you are developing, and for a production environment when you are in production.