The closest thing is Gimp#. Although many photoshop action files will not work with it.https://sourceforge.net/projects/gimp-s ... imp-sharp/
You will have to rename the downloaded file to exe instead of e_x_e for the setup to work.
You will also have to rename the gimp-2.6.exe file to gimp-2.4.exe so the installer works.
(then rename it back to gimp-2.6.exe) - if you need help with install PM me.
I am currently trying to compile version 0.18 for windows.http://maurits.wordpress.com/2010/12/02 ... -released/
All PS action files must be in the scripts folder to work.
Another close one is Gimp Scripter (you will need python).
Some people suggest using a recorder/playback tool to automate Gimp. Scripts from such tools break when the Gimp GUI changes, and the scripts are not easily distributable. Gimpscripter is an alternative.http://registry.gimp.org/node/25305
This plugin allows you to essentially use plugins to build another python plugin.