Access environment information in template Is there a way to check what environment craft is running on - ie, dev or not dev - via the template.

For example:

{%if env is 'dev'%}
    hello dev
{% else %}
   hello world
{% endif %}
In Craft 3 you can get the env using the getenv() function:
{% set env = getenv('ENVIRONMENT') %}

{% if env == 'dev' %}
    hello dev
{% else %}
    hello world
{% endif %}

Or via the app’s config service:
{% set env = craft.app.config.env %}

There's a bit more information about the .env file in the docs for Environmental Configuration.