iMacros are a series of recorded events that can do a series of things such as auto playing a game or creating Neopets accounts.
They are compatible with a mac and with windows.
Go to firefox or download it free here http://www.mozilla.com/en-US/firefox/
Go to tools < addons < get addons < search iMacros
Then download it and restart firefox
Open Firefox and with the iMacros open there will be a toolbar on the left filled with default preview codes
Now either create a new code or right click and edit a default preview code
Copy in the code
Now it does things automatically!