Turbogears2: analog of django context processors
You have three possible solutions to achieve this.
First you can use tg.tmpl_context which is available inside every template as tmpl_context.
You can fill the variables inside the BaseController.__call__ so that they are available everywhere. 
Another approach is to register base_config.variable_provider inside app_cfg.py which must be a function that returns a dictionary of variables that will be available inside any template. Those variables will be overridden from the controller returned ones if there is a name collision, so it is a good way to provide defaults for controller returned variables.
Otherwise in recent versions it is also possible to register the before_render hook systemwide using base_config.register_hook inside app_cfg.py the callback can append and override any template parameter.
Is there any analog of django context processors in turbogears2?
In tg1 was stdvars, but not in tg2 anymore.
Explaining:
I need to have some template tags, avaible on each page, without obvious declaring in each controller.