Net Express is installed as a single-user product onto each of your developers computers.

Each computer has a separate license key installed allowing that particular developer to use the product.

You can install Net Express onto a Terminal Server or Citrix environment but you must be licensed properly to do so.

In a Citrix environment a single copt of Net Express is installed on the Citrix Server and then each developer starts a unique session in order to run the product.

In order to run Net Express in this fashion you must have the License Server product installed that will distribute development licenses to your programmers each time they start a new session.

There are a couple of KB articles that you should take a look at:

Installing Net Express on Terminal Server or Citrix

Micro Focus Statement for running in Virtual Environments

I will leave it to others to comment about how well this works as I have never used Net Express in this manner.

Thanks.