Storing variables in a theme outside preprocessing I have some variables that I want to store in my theme, but I cannot always use theme_preprocess() to set and subsequently gain access to them.

What is the best way to do this?

I would like to not use a module, but with my experience in the past, a module has a hook_install() where an can use variable_set(); Is there anything similar for a theme?
I'm not sure if that's exactly what you're looking for, but Drupal has the concept of theme settings, which allow to configure a given theme with variables.

See http://www.metaltoad.com/blog/how-add-theme-settings-drupal-7 for a great introduction to them.

And according to theme_get_setting(), you can for example store defaults in your theme's .info file, something like

settings[your_setting] = the_value


Should work.