How to create a lightweight domain access alternative in Drupal 7 I have a password protected site mainly used for internal management of projects, but have regularly the need to publish some of its content for clients.

For simplicity sake, I would prefer to keep all content in the same database and site. However, the published content should be viewable from another domain name.

The contrib module 'Domain access' is too heavy for my needs. I'm looking for an alternative that 'simply' allows content to be published to a second domain using something like a setting or toggle per entity.

Experiences in this area are very welcome.
Out of the box drupal 7 installs are domain agnostic (don't save absolute urls in content or as paths). Assuming you haven't got any custom server directives or alternate domain with a need for a different relative url, you could try either:

A) Create a separate content type, if content managers know up front what content will need to be visible. 

B) But if they don't know up front (and since you can't easily convert a node from one type to another), you could try using a taxonomy field to tag content for visibility. Then use taxonomy access lite module (https://www.drupal.org/project/tac_lite) to grant access to nodes tagged with a specific term to anonymous users.